A/N: Everything I know about Reborn (from fanfic): He's an intellect snob, he loves coffee, he's the World's Greatest Hitman, he can read minds, he has a shape-shifting chameleon named Leon, and he's a mathematical genius who's got like, half a dozen degrees.

Everything I know about Zeref (I still haven't seen past Key to Starry Sky arc which means I have like two episodes of content and spoilers to base everything off of): He's a genius, he wants to die, he sometimes cares about everything and sometimes cares about nothing, he can care about people as long as he treats it like a game and them only like pieces to control, and he both loved and murdered Mavis (accidentally).

Things that are relevant to this fic that come from a massive FT AU I will write some day: Zeref is a good cook, Zeref is extremely touch-deprived and longs for physical contact, Zeref is attracted to highly intelligent people (he's asexual, but people who can keep up with him? Especially people who love creating new spells as much as he does? Zeref loved Mavis because she was warm and kind and caring, but also because we canonically know Mavis to have been very intelligent – creating spells and earning the name of Fairy General/Fairy Tactician over the course of a war, and in my AU Zeref loved her as much for that as for the kindness she offered him without hesitation), yeah, I like the idea of Zeref just geeking out with a life-partner over the complexities of magic, and I especially like that life-partner to be Mavis.

Natsu has to drag his idiot-genius older brother out for food sometimes, because Zeref tends to forget he's no longer immortal and will actually starve to death (not in this fic obviously but just… as a general headcanon that I like to wish was ACTUALLY canon).

Also, Zeref is an older brother, and in my AU due to a number of reasons those instincts were still very strong even 400 years later, which probably changes how I present his personality in this fic, when I'm using my AU Zeref just with a slightly changed up backstory to fit the 'verse. Part of that backstory has always involved Zeref's name actually meaning something – like, meta, it's just audibly similar to Seraph, but I always liked the idea that his name had meaning in a language in-story so I incorporate that into my AUs.

Yeah I think that's everything important. Enjoy this crazy hell-ship of mine or not as you will THIS IS WHY I DON'T WRITE AT 3 AM YOU GUYS.

"I can kill anyone."

It's not a boast, for all that Reborn lounges at the bar with particular arrogance. It's just a statement of fact, offered in response to some pathetic fool doubting his ability to do a job.

It's even true.

For as long as Reborn's been Reborn, he's never once received a target he couldn't kill. Some he wouldn't, perhaps, but never anyone he couldn't.

It's how he knows he's the best, for all that no one will call him such.

He tries not to be annoyed by it.

Killing clients is such bad form.

Which is why he's so irritated when someone scoffs in response.

"Yeah? I gotta guy you can't kill," the man says, boldly swaggering over to the bar and doing his best to loom over Reborn. He slams a hand down an inch from the assassin's drink and leans in close. "Ten billion jewels if you can take the head o'the Black Wizard."

The bar goes silent. Reborn tilts his head laconically.

"He hasn't been active for decades. People already say he's dead." The man's eyes narrow, though his lips start to twist into a smug grin. Reborn smoothly continues as though he never planned to stop. "Though if you have information to prove the contrary, well."

Reborn flashes his own smug smirk, lets it seep into his voice so the bar can't doubt what he means. Behind the mask, his heart rate picks up.

Whether it's panic or anticipation, Reborn isn't quite sure.

The things the Dark Wizard is said to be capable of… Reborn doesn't buy into the rumors, at least not all of them, but there are some things that are undeniable.

Reborn's studied spell crafting himself, knows how to make new magic from scratch, from circles and runes and not just learned forms, so all he ever had to do is have a close encounter with one of the Black Wizard's demons to know just how utterly genius the man is.

If anyone asks (which they don't, at least not anymore), he vaporized the demon utterly.

He absolutely does not still have it, alive, as a captive for study.

But oh every new thing he learns is just a wonder he never thought magic capable of, every new aspect pushing the boundaries of what is possible just because they can and it's worth all the money Reborn has to spend keeping the thing alive just to get a glimpse.

"Meet me here in two days," the man before him growls, no longer smug but still confident, "I'll have your proof ready for you by then." He turns and strides away, desperate to get the last word, so Reborn calmly sips his drink, and lets everyone else see how little he cares.

He leaves as soon as the cup's empty, though, because he can kill anyone but he rather wishes he'd had a little more time to plan for his new target and he can't afford to delay.

.

Two days later he steps into the bar to a veritable wall of people, though they quickly part when they recognize him. He wonders how many of them are there purely because they expect him to die, as he strides unhesitatingly through the crowd.

The man waits at the bar, and hands him a sparse file that Reborn sits down to read immediately. His… client, scoffs in outrage as Reborn peruses the papers, but he ignores the man.

He packs it all back up after a couple minutes, standing and brushing off his coat as the client gets more and more frustrated.

Reborn casts a casual glance the man's way, then speaks as he begins to walk back out. "I suppose your information broker is very good. I would agree, the evidence you've laid out does heavily imply that the Black Wizard is still at large. So I'll take the job."

The door shuts, adding a finality to his speech, and Reborn flips the file back open as he walks, studying it, because it's hard to kill a man if you can't find him and Reborn's not about to let that be why he fails this job.

He wonders what the Wizard looks like.

No one's ever seen his face and lived, after all.

Proving the kill to actually be the Black Wizard won't be easy, everyone refusing to believe it and no one knowing the man's looks enough to verify. But that's alright. As long as Reborn knows, he'll be satisfied.

Perhaps he could get the man to answer a couple spell crafting questions first? There's so many things he'd like to have clarified regarding that demon, after all…

And it would be tragic to kill his best source of information without even trying to learn.

Fairy Tail arrives onto Tenrou Island with the same zest they always do. It annoys him, if he's honest, but Mavis likes them having their S-Class exams on the island, likes being able to meet new members and see old ones, likes the proof that her guild is still strong, still flourishing.

He might not be able to see or hear her, but Zeref can tell when she wants to gush, and in a moment of distraction as Mavis spots Makarov, he teleports away, stumbling only slightly as he alights on the far shore of the sea. His entire body aches, tingling in that way that always means he used too much magic, but Zeref ignores it.

It's not as though it will kill him.

There's no real goal or destination in mind, he only left to get away from Fairy Tail and Mavis, and so he wanders aimlessly.

Skirting around towns and travellers, always far enough away to ignore them, Zeref tries not to think.

About the future, or the past. Tries not to look at nature and find it beautiful, closing his eyes to even the slightest hint of movement because animals are so much harder to ignore than plants.

He tries so hard to ignore everything, deep in some nameless forest three days' walk from the ocean shore, that he doesn't even notice the spell - or it's caster - until it rips through his skull.

Fire, he thinks, feeling it sear his brain with a near-boiling heat, vaporizing bone as though it was never there to begin with - and then he thinks nothing, for a long, blissful moment.

He loathes and loves lethal injuries that damage the brain. Because for a single instant, there's nothing, it's as close to death as he's ever been, and then he wakes up.

The headache that lasts for hours afterwards isn't fun either, if he's honest.

His eyes snap open, and he instinctively moves to track the position of the sun, because fire can be an unusual way to die, and he's actually been out of it for days before after burning.

Instead he sees a human's face as the man leans over him, golden flames dancing across his fingers, and in the time it takes Zeref to appreciate the sheer genius of the spell that hit him, he feels the curse surge.

He closes his eyes and tries to remind himself that he just doesn't care anymore.

Mavis is dead, and by his own hand. He doesn't have room in his heart for anymore guilt.

All of Reborn's instincts scream at him, and he throws out as much magic as he can, leaping backwards before he even knows why.

He stumbles, falling to his knees just outside the border that suddenly appears. His magic feels gutted, ripped from him and extinguished with no sign to show for it, and he shuffles backwards, just a little bit further away from the line that suddenly, clearly, divides a living world from a dead one.

His heart races in his chest, and he couldn't say if it takes a minute or an age, before the Black Wizard slowly sits up.

What was once a tightly enclosed forest space is now practically a clearing, dead and rotted and surrounded on all sides by fresh, living wood.

Distantly, Reborn thinks that if he survives this, he is going to dig up every rumor that ever existed because at this point he's ready to believe it.

And then the Black Wizard's meandering eyes land on him, kneeling at the tree line, still clutching his chest against the burning ache that is his magical core - and widen in surprise.

"You're alive," he says with soft wonder, and Reborn wonders if people surviving the first strike is so rare as to warrant that sort of reaction.

Gods that must be so boring.

Reborn doesn't tense, tilting his head casually to show he's listening, as he drags up every ounce of magic he has left. It burns, scraping him raw from the inside out, but he has no intention of dying here.

The Black Wizard sighs, looking away. "It won't do you any good. I can't die."

He says it with the same surety that Reborn said, "I can kill anyone," and none of the arrogance. Clearly, though, the man has no intention of killing him just yet, so Reborn stands up, dusts himself off, and strides forward. He makes it two steps before having to throw himself backward yet again, and he watches as the wave of pure death goes just a bit further this time than it did the last.

When he looks up, the Black Wizard is watching him again, one eyebrow raised in wry amusement. "You're good," he offers with a smile.

A smile.

Reborn wastes precious magic scanning himself for drug or spell residue.

He finds nothing.

The Black Wizard stands, and Reborn wonders if their peaceful dialogue is over.

But the man doesn't make any move towards Reborn, just rubs at his head, dirt and ash flakes falling from his hair.

There's not even a bald patch to show for Reborn's perfect kill-shot, and he's offended.

The Black Wizard looks back up, confused. "You're still here? Do you want me to kill you?" He asks it with a mild curiosity, like the idea of someone wanting to be killed by him is a novel idea and he's willing to see where it goes.

Somehow, Reborn gets the feeling the guy doesn't actually interact with his own worshippers very much. Some of them are absolutely the sort of people who would commit suicide at the man's feet just for the pleasure of dying in their god's presence.

None of this is going the way he expected at all, and Reborn did want to ask some questions on spell theory…

He leans casually against a tree, and idly inspects his hand. "I actually had a couple questions, if you don't mind," Reborn offers, and the Black Wizard tenses.

Reborn very pointedly doesn't tense in return, and waits patiently. He's treading on thin ice here, trying to chat with the most dangerous man in the world, he can afford to take things slow.

"Do you try to kill everyone before you question them? The years blur together, but I'm fairly sure the necromancer's guild was annihilated centuries ago."

"There was a necromancer's guild?" Reborn abhors parroting, but he's practically friends with Vongola, one of the oldest criminal organizations on the planet, and he's never heard of such a thing.

A Guild implies multiple mages. Multiple successful mages, with the way the Black Wizard referred to his kill-first-ask-questions-later approach, which means that Necromancy must have existed as a legitimate branch of magic at some point, and all of Reborn's intellectual curiosity sits up and takes note.

He wonders if the Black Wizard was a part of the guild, or perhaps its founder, or just alive at the right time to know of it. And the man answers without having to be asked, shrugging casually as if to brush off the question. "The Magic Council raided it after they started moving away from the more standard branches of Necromancy and began looking into my more… esoteric research. I know the Council also defamed them and branded their entire legacy as criminal, though I hadn't realized they've been scrubbed from history…" he trails off with an idle look into the far distance, and Reborn's never actually met an immortal before so he can be forgiven for only just now wondering what it must have been like.

So much history as it actually happened, uncensored by any party, standing right in front of him, and Reborn wonders how much the Wizard was there for, how much he saw and experienced that the rest of the world has long forgotten.

The other man blinks off his stupor after a moment, glancing back towards Reborn. "What did you want to ask?"

Reborn would like to step closer, draw runes out and properly discuss them, but he stays where he is. "It's actually about your demons," he starts, and pretends to be blind to the way the Black Wizard tenses all over again, "I was studying one and I noticed you used an unusual matrix. Layering a Kaldric formula with Hyppel runes, and binding everything to a triangle's base instead of a circle… The triangle I understand, but the matrix? If you had a moment, I thought I might… pick your brain on the matter."

The pun is perhaps a little beneath Reborn's dignity, but the Black Wizard snorts an ungainly laugh and turns to properly face him, pulling a light pen out from behind himself as he does.

And then he starts talking.

The light pen changes color with little more than a thought from the Wizard, and Reborn's pretty sure it's custom-modified because he hasn't seen any like that on the market, and he spares a moment to wonder how, but then he's lost again in numbers and runes and equations enough to make even his head spin as the Black Wizard talks from fifteen feet away and draws on the air backwards and large enough to read without any effort.

The sun sets and rises again, the air glittering with thousands of figures, still floating, when they should have faded hours ago, and Reborn wants more. Already he has ideas for customizing his own magic, tweaking his spell bases and improving them, and the Wizard just keeps going, alive and animated and completely in his element as he breaks down complex equations into something magnificent.

The guy straight up invented his own runic language and Reborn needs to know how he did that, thinks the rumors that the Black Wizard has control over True Magic might not be rumors at all if he can tie his own made-up runes into the very fabric of magical reality -

The Magic Council gatecrashes their discussion with all the finesse of Deliora, and Reborn just might hate them in that moment.

The Wizard sighs, lowering his hand as he turns to face the sounds coming through the trees, loud and unignorable. "I do believe I lost track of time," he muses, and Reborn can tell from his voice alone that they won't be picking this discussion up and moving somewhere else.

He wonders if they could, if there are enough customizations on that light pen that they could just take the text with them and relocate, but the chance has long since passed him by.

"Well, it's been fun," Reborn starts, calling out for Leon telepathically, "but I've still got a standing job to assassinate you, so if you could… not disappear off the face of the map again, I'd like to give it another shot."

"Am I to reward your failure with a lecture?" the Wizard asks, eyebrow quirked even as he vanishes their text with a wave of his hand.

Reborn mourns the loss, and feels Leon crawl up his leg as he replies, smugness coating his tone. "I can't promise not to use it against you."

"You can't kill me," the Wizard rebuts, a teleportation spell already whisking him away, and all Reborn can think is-

That wasn't a "no".

Zeref should have teleported back to Tenrou. The human - an assassin? - has no chance of killing him, and allowing him to even try again is a waste of time and will likely only only end with the man's death.

He tries to tell himself that it's purely because the assassin brought up some interesting points, and he wants to cross-reference a few books to find an acceptable answer.

He grabs the thin threads of hope that try to take root and strangles them.

It will be years yet before Natsu and the others come through the gate, and Natsu is the only one who can kill him. Hoping for anything more, anything faster, is foolish.

He gets the books he needs, and a few others that just looked interesting, and finds an expansive clearing two countries over in Bellum.

Food is meaningless to him, a simple pleasure that only serves to remind him of how very human he is not, so he takes his books and blank journals, throws up a barrier to keep out dew and moisture, and loses himself in study.

It might have been as long as two weeks, he thinks, when the lance of fire rips through his spine and spreads, searing all his internal organs and attempts to burn him up from the inside.

The craftsmanship that must have gone into the spell, to make it expand on its own internally instead of ripping through the other side to damage the books is astounding, but Zeref finds himself disappointed that the assassin chose such a method.

Clearly, he decided the knowledge was more important than trying to seriously kill Zeref, and he finds himself… more hurt by that than the physical agony of fire trying to devour him from the inside out.

And then there's a boot striking his ribs, kicking him away from the books, and a second spell linked to the first, and the fire changes.

He chokes on a scream, can't even figure out what sort of alteration the assassin made to the spell from the mind-breaking agony of it, and then-

It stops. In that instant sort of way pain does when he should have died but didn't.

He takes a moment to breathe, shaking off the last mental vestiges of pain, before slowly sitting up.

He can still feel an echo of the assassin's hands on him as the man wove his second spell, burning like a brand in the back of his mind.

When he looks around, he finds the assassin standing twenty feet away and looking decidedly put-out.

Me too, he thinks in commiseration, because whatever the man did was brilliant and it should have worked, if this world were fair at all.

He already knows he'll be back a third time, as he slowly drags himself to his feet.

That sort of ruthless genius…

If anyone could stand a chance…

"I suppose I should ask your name," Zeref muses aloud, "If this is going to be a regular occurrence."

Reborn won't admit to the single moment of regret he feels, when the Black Wizard's scream cuts off with a distinctive finality.

Perhaps mostly because the man keeps breathing afterwards, and it is both utterly unfair and absolutely fascinating.

Reborn's professional pride as an assassin is absolutely smarting by now, but that part of him that loves learning and expanding his horizons practically purrs in pleasure.

And then the Wizard stands up, looking for all the world like a man dragged unfairly from his nap, and asks for his name.

He considers for a moment, but… well. If this is going to be a regular occurrence, it would make things easier. "Reborn," he offers, and the Wizard snorts another ungainly laugh at the irony of it as Reborn continues, "But I have to wonder - there seems to be some debate as to whether Zeref is even your real name, especially considering the… linguistic roots." He smirks as he says it, just to make sure his companion knows exactly which linguistic roots he's talking about, and doesn't spare any time to worry about whether that's a killable offense.

All the best assassins court death, after all, and while there isn't any actual debate over the Black Wizard's name, Reborn meant it when he promised to research everything, and he really has to wonder.

It's not every day you find something as priceless as the idea that the world's most feared criminal is named gentle in some archaic, backwater language most people have never heard of.

And the feminine emphasis of gentle at that.

But the Black Wizard doesn't kill him for it, only stares in surprise. "How did you know it was Ethelian? I'm fairly sure most people reference it as having Caelium ancestry."

Ethelos was a country wiped off the map over six-hundred years ago, long before the Black Wizard was supposed to be alive, and Reborn only expected a man disgruntled at Reborn deliberately mistranslating his name.

With the Wizard's pale skin and sharp features, he could pass as ancient Caelum nobility. And Zayef, the closest traditional name to Zeref in the peninsula, translates to a much more fitting comfortable darkness. The modified 'Zan', for darkness, and 'Yeffa' for comfort or shelter.

The idea that the Black Wizard might be from the continent is nearly enough for Reborn to turn around and get right back to researching the man, because clearly all his sources are wrong.

He pushes down the urge with the thought that the Wizard hasn't tried to kill him from asking questions yet.

"The languages is about as dead as you should be, so I figured you two had something in common," Reborn offers, because why admit he didn't expect this if he doesn't have to?

Zeref huffs, shaking his head. "My father had Ethel heritage, and wanted to keep to his ancestors' old naming traditions. Nothing more than that." He pauses for a moment, stepping forward to pick up a book. "I looked into some things you said last time, and I believe I have a better answer now to your question of the Stygthian concentric circle formula. We can start there, unless you had a different line of questions?"

Reborn shakes his head, eagerly moving closer, until he's standing at the comfortable fifteen feet they did before, and he pulls a notebook and pen out of his bag. "Whenever you're ready."

Zeref grins, wide and boyish, and Reborn has perhaps a second to wonder how old the Black Wizard physically is, before the man proceeds to blow. His. Mind.

He's certain, in the distant way of someone utterly distracted, that he'll be dreaming concentric circles for weeks.

It's so easy to forget, being immortal, that other people need such irritating things as food, and water, and bathroom breaks.

But Reborn is brilliant, and doesn't shy away from the sometimes dark places his brain goes when he's spellcrafting, treats an offhand comment about destroying an island in an experiment as exactly that instead of freaking out for two hours straight, Mavis.

It wasn't even like the island was inhabited, for all that Reborn doesn't ask, and their lesson/debate/conversation continues until they run out of food for Reborn to consume.

The assassin looks as visibly annoyed as Zeref feels, and, well… it never hurts to offer.

"Regrowing limbs isn't too difficult, when you're functionally immortal." he states, holding out his arm. And then pulls out the best 'evil smirk' he can, just for fun. "I promise I'm not poisonous."

It actually takes an entire second for Reborn's brain to process, which is the slowest Zeref has seen the man. And then Reborn's face contorts into the clearest expression of what-the-fuck Zeref has ever seen on a human. He schools it quickly into a more sophisticated look, lifting his chin and looking down his nose at Zeref, but the wizard can still see his shock.

"Thanks, but I don't know where you've been."

The unsaid, "You mongrel," lingers in the air between them, and Zeref can't deny the amusement curling through him.

"Until next time, then," he offers, scooping up his hand-written notes and leaving the other books behind as he lets his magic whisk him away.

He'll have to remember to ask about the spell Reborn used, next time.

It totally slipped his mind.

What the fuck. Reborn thinks as Zeref teleports away, leaving him with a pile of books and the last two minutes playing on constant repeat in his mind.

What. The. Fuck.

He sways on his feet, forcibly reminded that they stopped their conversation because he was legitimately light-headed from hunger, and he needs to start moving now if he wants to get back to civilization before something decides he's easy prey.

Zeref never ate so much as a bite, never even looked the slightest bit hungry, and some hysterical part of Reborn wonders if the man is, in fact, a god.

He reminds himself that Zeref has a father, and a girl's name, and that neither of those are indicative of godhood.

He really needs food.

And he can't help but wonder what Zeref tastes like, because Reborn has never actually engaged in cannibalism but the man went and made the offer as though he was handing out tea and biscuits and now Reborn can think of nothing else as his stomach churns in its incessant desire for food.

When he goes to kill the Wizard again, he's going to make it hurt even more, going to make sure he sees Zeref scream until his throat tears and he drowns in his own blood, and until then he is going to hunt down every surviving record of Ethelos he can get his hands on because he now knows more about the Black Wizard than anyone else on the planet and he's not going to let that go to waste.

But first.

The books.

Every time they meet up, Zeref expects Reborn to give up on killing him, to maybe offer a token effort before delving straight into their theory debates. And every time, Zeref finds himself surprised by the sheer brutality Reborn brings to bear in his attempts to kill the Wizard, sometimes with absolutely inspired spells that Zeref happily spends hours picking apart and pointing out improvements for.

He wonders if this is what having an apprentice is like.

And then he reminds himself that he Does Not Care, and this is just a means to an end, and that when Reborn inevitably stops trying to kill him he'll just kill the assassin in turn and move on.

Eight and a half months into their… unusual acquaintance, Zeref wakes up from his nap to the disconcerting sensation of being a bodiless head, and has about half a moment to glare at Reborn for the annoyance before the magic lances out at point-blank range and renders all thought literally impossible.

When awareness pieces itself back together enough for him to sit up, Reborn groans from their customary 15-foot distance. "You were dead for ten minutes this time, that's just not fair."

Zeref can't help tilting his head in curiosity, feeling the burn of freshly-stretched neck muscles. "You must have done something more fascinating with the spellwork than I could detect. It usually only takes three to four minutes to recover from having my head vaporized."

"Amateurs," Reborn scoffs, immediately launching into an explanation of his magic, and Zeref's not about to say he did it to himself if that's the attitude Reborn plans to take.

Really, the most enjoyable part of that experience was figuring out how to properly inflict that sort of damage on himself.

It was a lot harder than he expected, for sure.

The conversation meanders from there, seamlessly migrating from Reborn's spell to the latest theorems Zeref's been studying in the downtime between assassinations.

He'd forgotten how alive learning made him feel. There are days, so deeply buried in his books and spell theories, that he honestly forgets he wants to die.

And remembering always hurts twice as bad.

Reborn pulls out a picnic basket two days into their debate and tosses a piece of fruit at him, effortlessly derailing an argument he was trying to make for using the Myrcella theorem over the Accaron for a long-distance telepathy spell.

Zeref stares at the red apple in his hand, honestly befuddled. Reborn scoffs.

"Don't tell me you've forgotten how to eat."

"I haven't," Zeref replies, rolling the apple between his hands. "But I don't need to eat."

"I hadn't noticed," Reborn utters, deadpan. "But you've touched it now, and I still don't know where you've been. So either eat it or throw it away."

Zeref shrugs, and eats the apple. Reborn's hawk-like stare bores into him, and the assassin doesn't touch his own food.

Zeref's not sure what poison coats the apple, though it certainly makes the fruit taste rather bad, and he burns the core to nothing once he's done.

Reborn sighs. "I suppose I shouldn't have expected that to work."

"It doesn't seem to have done anything at all. What sort of poison did you use?"

"I didn't," Reborn responds, finally digging into his own food. "I put a spell on your body while you were busy being dead, and coated the apple in a reactive potion. I guess the spell didn't last through whatever magic you have configured to bring you back."

"Oh no," Zeref counters, picking up his light pen again. "If you'd successfully applied the spell, it would have stuck around. I'm just naturally resistant to certain types of magic. I doubt it ever properly anchored to me."

It might be a dangerous hint to offer, when Natsu is only a few years away and will have many of the same natural resistances Zeref does, but the considering look on Reborn's face promises something fascinating, and Zeref can always kill the man if he oversteps himself.

They dive back into their debate with gusto, Reborn occasionally plying him with food, and when Zeref asks the assassin scowls. "I refuse to be the only one taking bathroom breaks." Zeref laughs, caught off-guard by the sheer offense in Reborn's tone, but eats the food anyway.

He tries not to think about the last time he ate food with one hand and wrote out spell theorems with the other.

He doesn't have much success.

It feels like the entire criminal underworld knows about his attempt to kill the Black Wizard.

It's his own fault, he stumbled unexpectedly onto Zeref in a book shop, collection of tomes in-hand, he was within touching distance and hadn't even been noticed, and he'd already made up a new spell after their last meet-up, and figured he'd just… try.

Four hundred and sixty-three dead people and no study session later, he thinks he should probably keep their assassination attempts to more private areas.

Reborn escapes the death magic by the mere skin off his teeth, so close he's fairly sure his authentic leather shoes wilt, and he stumbles desperately in a forward lunge, leaping off the high bridge for just a little bit more distance between them.

Definitely a no on the public-places assassinations.

He floats in the river, because water has insulating properties against certain types of magic and it's worth a shot, which means he has a perfect view of Zeref when he peaks over the bridge railing.

Reborn considers playing dead, because the guy is probably pissed, but he's never really been the cowardly sort so he offers a cheerful wave instead, blowing raspberries just because he can.

Zeref scoffs and walks away, arms loaded with books, and not for the first time, Reborn wonders if he even knows what rules they're playing by.

It's a game, of some sort, that much is obvious. And if Reborn loses, Zeref will kill him.

He just wishes, in all the ridiculous things cultists have spoken of in regards to their so-called god, that they'd managed to come up with a rulebook he could use.

He can't cheat if he doesn't know the difference between what's against the rules and what qualifies as losing.

He groans, idly backstroking down the river. His right foot is going numb, which is… concerning, but he's got a medical contact in the next town over who should probably be the first to touch it.

How convenient that the river runs past both.

But, less than a week later, everyone knows his ill-devised attempt to assassinate Zeref.

Which, on the one hand is nice, because it means his client can't keep calling him a liar when he says he's made multiple attempts.

On the other hand…

Reborn survived after attempting to kill the Black Wizard.

And now people believe all those times he said he tried before.

Reborn has survived multiple attempts against the Black Wizard's life.

And he isn't dead.

He can barely take two steps in any city without being swarmed. The Magic Council wants to bring him in, the cultists want to question him, other assassins want to kill him (which is, at least, nothing new, but he's never had to deal with so many at once before and ends up having to use some of his newly-invented spells to keep up), and, of course, it seems as though the entire black market for freelance assassins wants to hire him.

The guild recruiters learned a long time ago that no means no, and only two try their luck. They die spectacularly, but he can't handle potential clients the same way, much to his eternal frustration.

And so, the next time he actually has enough free time to try again, it's already been three months. He hopes Zeref hasn't wandered off to whatever hiding places he prefers, especially since their first-murder anniversary is right around the corner.

He'd hate to be the only one to remember, after all.

Zeref doesn't quite know what to expect when Reborn fails to show up within the three-week average they usually work inside.

-The small of his back still feels warm, like a brand in the shape of a hand against his skin, and he still can't help but wonder at the fact that Reborn got so close, triggered his curse, and still managed to escape unscathed.

He tries not to think about all the other people who weren't so lucky, strangers just caught out as victims of his inability to stop caring-

A month and a half passes, and Reborn still doesn't show. Zeref collects more books, continues to lose himself in studying, and tries to be patient.

Three months in the mountain of books is four rows deep and rises to his hips on all of them, a fifth stack off to the side filled with his own notes and diagrams.

He should leave, return to Tenrou island to wait out Natsu's return in isolation like he'd planned, but some foolish, tiny voice keeps whispering, "One more day," and he can't bring himself to ignore it.

Three months, one week, and four days after that disastrous attempt in the city, Reborn's return is heralded by an explosion of agony in his leg sharp enough to make him cry out as he falls to his knees.

He recognizes the taint of Dreyv root in the wound almost immediately, and thinks that maybe he should have warned Reborn about that.

It's not going to kill him, but gods and spirits it's going to hurt.

And then there's a second shot, right at the base of his neck, and fire, because Reborn is a sadist and Zeref will not believe otherwise.

He screams until death takes him.

Zeref sounds like a child when he screams.

He sometimes looks young, but for the first time, as the Black Wizard shrieks and shrieks and shrieks, Reborn honestly, truly questions how young.

Because those screams could never come out of any man's throat after puberty.

He thinks, hysterically, of Zeref-The-Immortal-Teenager, desperately trying to teach himself how to keep his voice from breaking even though his body won't age enough to properly settle his register, and wonders how likely that is.

The screams cut off with an abrupt finality that has Reborn setting a timer.

And then he waits.

An hour passes, then two, and Reborn begins to wonder at his success. Leon crawls closer, trying to investigate his human's new companion/target, but the assassin scoops up the lizard before he can.

"Not yet Leon," he chides. "We'll give it til sunrise before we count our success, hm?"

It seems logical enough to him, at least. Zeref uses classical magic, magic bound to the cycles of the moon and sun and seasons. Slower, but more powerful in so many ways. Dawn signals new beginnings, change for the better, and if Zeref's magic hasn't brought him back by the next sunrise, then and only then will Reborn mourn.

In the meantime, he's got a trouble-seeking lizard to entertain.

He doesn't want to think of what Zeref would do if Leon ate the books.

He usually spits them back out intact, but Reborn doesn't want to be the one explaining that to Zeref of all people.

Especially when the Wizard might want to experiment.

.

Four and a half hours later, just as the last rays of the sun's light disappear from the earth, Zeref stirs.

And Reborn wonders what sort of immortality magic would bind to the cycle of sunsets instead of sunrises.

He makes a note of it on a blank page in his book, because that sounds downright suspicious.

Reborn is the greatest assassin in the world, and no matter how much he's starting to like the Black Wizard, he's not going to stop until the man is dead.

He can always mourn later.

For the first time since the day he woke up cursed, Zeref is dragged back to life still hurting.

The sheer novelty of it has him laying there, shifting limbs and trying to figure out why.

He never hurts after he's revived from death.

Hope kindles like a treacherous flame within his chest, and he speaks ahead of his thoughts.

"Everything hurts."

"Oh?" Reborn's voice asks, pitched to carry over distance. "I would imagine so, considering how you screamed."

Zeref laughs, and feels his throat burn at the motion. His voice is still hoarse from screams, and it's honestly exciting. "I never hurt, after I come back. But…"

"Indeed," Reborn muses, and Zeref hears the scratching of pen on parchment. "Any particular aches or pains that stand out? Anything you don't remember feeling before? Or perhaps anything that is suspiciously free of pain?"

"You sound like a physician," Zeref complains, though he thinks over the questions regardless. "Nothing stands out though. Except…" he trails off, trying to place the sensation, and Reborn stays quiet, letting him gather his thoughts.

"I think I'm… craving?" Zeref asks, more a question than a statement, and his stomach gurgles faintly.

"You're hungry." Reborn says with utter deadpan, and Zeref painstakingly rolls over to look at the man.

"That… sounds likely," Zeref responds, still confused.

It's been so long, after all.

How odd.

A picnic basket bops into his head, and Zeref startles, scrambling to catch it out of the air. Across the field, Reborn grimaces as he stretches out his fingers, a purely psychological response to strenuous magic.

Zeref's done it no few times himself, before he just stopped caring.

"We can chat after you eat then," Reborn encourages, when Zeref just stares.

He jerks his gaze down to the basket, and decides to dig in.

He's not even sure he tastes it, honestly.

Zeref eats like a hungry teenager, and Reborn adds one more tick to the, "never made it past puberty" box.

And he eats a lot.

The brat looks downright mournful once he's eaten everything, nevermind that was enough food to last Reborn two weeks!

How he wishes the asshole weren't so paranoid about his personal space so Reborn could just march over there and strangle him bare-handed.

Sure, it wouldn't work, but at least it'd feel good.

Zeref has the audacity to not even understand why he's angry, when they start talking magic.

Reborn's not about to waste his time explaining.

He wonders if it would count as losing the game if he kills Zeref the exact same way next time too, just so he can properly appreciate the screaming.

Probably.

Pity.