I'm surprised no one called me out on the gang not living in Bellwood. Arcadia Oaks, California is the setting for this story, a town with a ton more to it than meets the eye which Tales of Arcadia (Trollhunters/Wizards/3below) fans will be familiar with. If you haven't watched these shows, don't worry; I'll explain whatever needs explaining as the plot goes along. If you don't like these shows, well, I did warn y'all about the multicrossover deal. I chose this town for reasons that will become important down the line (and because I've written most of a Trollhunters AU which takes place in this universe), so I hope you stick around that long.

Without further ado, here's the chapter!

Ben's entire body glows an intense, neon green for a full minute after the Omnitrix wraps around his wrist. It doesn't hurt, merely causing his skin to tingle a little, but he does make the wooden floor under his feet smolder, so he rushes out to the backyard, his clothes starting to smoke.

The glow subsides as soon as the others catch up to him. Ben stares at the object on his wrist, which seems to be processing something, judging by the way its faceplate keeps spinning around. He tugs at the skin around it, finding that the watch has indeed fused with his body. It doesn't hurt, either, but knowing that he'll likely never see that wrist again is kinda sobering.

"Well?" -Julie asks. "Do you feel any different?"

"No." -Ben says. He closes his eyes, trying to feel for any changes aside from the small, added weight on his left arm. "Not really."

Gwen pulls his arm towards her, examining the watch closely. "So...what does it do, exactly?"

"It gives me alien superpowers, apparently."

"Doesn't look like much." -Kevin notes. "How's it work?"

"Yeah, what alien powers does it give you? Can it give you magic like mine?" -Gwen asks.

Ben winces. "I...have no idea. Probably should've asked Grandpa."

"Well, it does have some buttons on it." Julie says. "Press them, see what happens."

Ben does. The Omnitrix chirps in response, but nothing really happens. In the back of his mind, Ben knows it's working as intended - he can't quite figure out why he knows though, and that's cause enough for concern.

Kevin rolls his eyes. "Great. Watch's busted."

"I don't think so." -Julie says. "I think it might be...updating."

"What do you mean?" -Gwen asks.

"Well, your grandfather wore this for the last time...what, thirty-five years ago? Maybe whoever made this thing pushed some updates over the last couple of decades." -Julie reasons.

Kevin rolls his eyes. "It's not an iPhone."

"Well, no, but it's still a piece of technology, with it's corresponding hardware and software."

Ben shrugs. "Even if that wasn't it, I'm not like Grandpa. Physically or mentally. It's probably just adjusting to me."

Before Gwen or Kevin can argue otherwise, the watch face stops spinning, making a bloop-bloop noise that Ben, again, somehow knows means 'ready'. He taps the button under the faceplate, and the latter suddenly springs up, the hourglass design changing into a rhombus within which a black, humanoid shape forms, complete with tiny, surrounding alien text that he can somehow read. The watch beeps constantly, insistently, as if it can't wait for Ben to use it.

"Any of you guys know what a Pyronite is?"

The other three teens all shake their heads, fascinated. Ben takes a deep breath. "Well, I guess we're about to find out."

He's about to slam down his palm on the watch to activate the process - and why does he know to do this, what the hell - when Julie stops him. "Wait!" -she says. "Are you absolutely sure you wanna do this? None of us will judge you if you back out."

"I will." -Kevin says, smug, which earns him an elbow to the ribs from Gwen.

Ben smirks. "It's ok, guys. I'm not really sure why, but I know this. The Omnitrix is...familiar, somehow. Grandpa said it was always meant for me. No idea why that's the case, but it definitely feels like he was telling the truth."

Gwen purses her lips. "Alright, just...be careful. Grandpa's funeral was rough, and he's still alive out there. Don't make me bury my best friend."

Kevin nods, rarely seen seriousness permeating his expression. "Or my brother."

"Or my lover." -Julie says. When she sees Gwen's scandalized expression, she giggles. "What? It rhymed, Gwen, don't worry about it."

Ben smiles at the broken tension. "I know I don't say this enough, but...I love you guys. If I don't make it...well, I'd say 'tell my parents I love them', but I don't think they'd buy it. Find Grandpa, and tell him instead."

He closes his eyes, raises his hand, and, as he slams his palm down on the artifact on his wrist, says, "It's hero time."

All that Gwen, Julie, and Kevin can see of the process is a blinding flash of neon green light, as Ben's entire being is rearranged to match the physical profile of a Pyronite, but to the rest of the galaxy, and perhaps even beyond, the Omnitrix's first activation in decades is a short-lived but utterly massive beacon, a siren's call that none can ignore.

The Bounty Hunters' Guild on Knowhere immediately whips up into a frenzy, mercenaries and cutthroats of all shapes and sizes rushing to claim the long-standing mark on whoever has become the watch's bearer; the Kree fleet blockading Earth rushes to report the event to the leadership at Hala; SWORD's orbital command center, Ascalon, comes to renewed life as they struggle to make sense of the Omnitrix's signal; and of course, the massive dreadnought Chimaera, half buried into the scar it left upon the martian moon of Phobos' surface, begins to dig itself out of its decades old grave, immediately sending out a probe to pinpoint the location of the fabled watch for its dark master.

The change only lasts a second, but Ben's mind still experiences flashes of another creature's lifetime.

He sees others like him - them, Ben realizes, feels more appropriate to describe the genderless Pyronite - people he instinctively knows to be the alien's family. The creature he's becoming is small, then, and those around them tower over their short stature. Their bodies glow green, a familiar temperature, tapering off to to the cyan of their eternally blazing fringes. Then the alien grows, and the creatures around them change; they're no longer surrounded by the comfort of a home, and the mass of people around them reflect the change. None of the aliens around the Pyronite seem to glow at all, core temperatures too low to register as anything more than a purple-black void. The last thing Ben sees of the past is a fight - their hands streaming white torrents of flame, lighting similarly dark figures ablaze. They glow only for a moment, which Ben knows won't last long. Soon, all that'll be left is a cold, empty void in space, in the shape of those they've burned.

As soon as the hallucinations - memories? - end, Ben opens their eyes to fire, smoke, and a couple extra feet in height. Everything around them is the wrong color; the grass that should be green is nearly black, and their friends are various shades of dark blue and purple. They look down to see that the Omnitrix itself has disappeared, but the symbol on its faceplate has become an emblem on their chest. Their body is igneous rock, appearing bright green to their alien eyes, white cracks all over their body betraying their inner power. Their hands have four digits, while their feet have only two.

"What's with the name?" -the taller person asks. Kevin. They know this, come on. They may have just turned into an extraterrestrial lifeform, they may be setting the ground beneath their feet on fire - hell, he may not even be a he anymore, but they're still Benjamin Kirby Tennyson.

"The name?" -they ask. The Omnitrix pulses softly with his words - alien words, instantly translated to english. He sounds kind of like a grizzled action hero, which he's definitely ok with.

"Yeah, you shouted 'Heatblast!' when you finished transforming." -Kevin says, raising an eyebrow. "Real hero-like, too."

"Oh. That's just my...our? This alien's name." -they say. Ben's pretty sure that the Pyronite in the flashbacks wasn't called Heatblast, but the being they've turned into definitely is. It just...feels right.

Gwen frowns. "What do you mean, our?"

"It's hard to explain. It's like they're...in here, somewhere." -they say, tapping the side of their head. "Whoever this body was based on, maybe."

Kevin raised an eyebrow. "So what, you've got an alien hitching a ride on your brain?"

Ben shakes their head. "No, that's not how it works. I think...I think if I'd turned into a Pyronite without this weird...connection, I'd have to relearn everything. Walking, talking, fighting. Whatever my body is capable of, now."

"And? What can you do?" -Julie asks.

Ben hums. "Well I think I see in temperature, for one."

Their girlfriend tilts her head. "Come again?"

"Yeah, like those thermal vision cameras, or goggles." -they say, then gesture toward the others. "You guys look dark, like you're really cold. My hands look green-ish. So did the other Pyronites I saw in this guy's life's highlight reel."

Gwen crosses her arms. "Huh. That's a really useful power. I bet you can see people who're camouflaged, or even invisible."

Ben gasps, excited. "Like the Predator!?"

The redhead rolls her eyes. "...sure. I guess."

"That's neat and all, but I don't think it's gonna help you actually beat up the bad guys." -Kevin notes.

"Don't worry, I've got something for them." -they say. They pool a bright, white-hot ball of plasma between their hands. "Like this!" -they say, and throw the ball straight up at the sky. The glob flies much too far and fast for the alien not to have some kind of superior strength, and then bursts into wild flame, almost instantly dispersed through the air. They then blast a stream of plasma from their palms, a shorter ranged flamethrowing attack that sounds like a raging furnace, and has the others backing up to avoid the worst of its convective heat.

Julie grins. Beads of sweat have popped up all over her forehead, as well as Gwen and Kevin's. "This is so cool!" -she says. Ben winks at her. Heatblast can't blush, but their flames do seem to burn a bit brighter for a second.

"I'll admit it: that's impressive, Tennyson." -Kevin nods. "Should probably turn it off though, before you set the forest on fire."

Heatblast hesitates, looking at the smolders beneath their feet. It's slow going, thankfully, because the plant life around them is still green from spring and summer, but they're not getting any less hot. "Uh...I don't...I don't know how, exactly."

The first few flames start flickering beneath Ben. "Oh god, that's not good!" -they panic a bit. "Quick, put me out!"

Julie bolts for the nearby hose, and blasts Ben with extreme prejudice. The water immediately evaporates though, even before touching Heatblast's rocky exterior. Ben's expecting it to hurt, but they can't even feel it, and their fiery corona isn't diminished at all. The grass stops burning, at least.

"Jesus, what the hell?" -Julie mutters. "Oh, I know! The lake!"

The lake is more of a glorified pond, but it's only a half mile away or so. It's secluded, too, but that's less of a priority right now, admittedly. The four of them start running, Ben's naturally longer legs granting them an instant lead. It only takes Heatblast about half a minute to get to the lake, into which he immediately cannonballs, leaping several dozen feet in a single bound.

The water hisses explosively upon contact, sending a sizable column of superheated vapor spraying away. Ben sinks all the way to the bottom; their body is heavy, owing to its dense mineral composition. Ben's at least thankful that they don't seem to be drowning or suffocating, but the flames don't seem to be going out at all. A sphere of magenta energy encircles them, trapping them with instantly boiling water. They're pulled out of the lake by Gwen, who's floating above the surface, and deposited on the shore. It's hardly a solution, since the sand and rocks are already starting to melt.

"Thanks."

Gwen shrugs. "I did it for the poor, boiling fishes."

"Okay…well, we're in panic mode." -Ben admits. "We need to figure something out fast, or I'll have to move to the nearest volcano."

Kevin and Julie catch up to them, looking winded. The older teen has the Omnitrix-themed badge, and quickly brings up the holographic data. "I think there might be a way to get you back to normal, Ben."

"You're not gonna like it." -Julie warns. "Kevin might, though."

Ben kicks at the liquid glass and actual, literal lava under their feet. "I don't care! Do it!"

Kevin shrugs. "I mean, if you insist." -he says, then absorbs the alien metal from the badge, and charges. Before Ben can even begin to figure out what the hell Kevin is doing, the Enhanced decks them, his fist connecting with their chin and sending them sprawling with a groan. Kevin doesn't just become whatever material he touches; his strength and durability adjust accordingly, so the hit definitely stings. Ben thinks it might've even cracked their rocky jaw.

"Kevin!" -Gwen cries, landing protectively beside Heatblast. "What gives!?"

Kevin smirks, even though he shakes his hand in pain. Just the minor contact heated the metal up enough to glow a little. "Max's notes warned that the powers might wear out if Ben takes enough damage. Figured I'd punch some humanity back into him."

"That's a terrible solution." -Gwen chides. "There must be another way."

"I mean, I was just skimming on the way here, so probably." -he admits. "But will it be as funny?"

Julie rolls her eyes. "Let me check that badge again."

Ben rises while Julie mutters her way through what looks like gigabytes of entries. "Damn. That was weirdly impressive."

Kevin crosses his arms. "Thanks." -he says, drily.

"Not you. Well, yes, your powers are never not awesome, but I meant me this time. That kind of hit can punch right through walls, right? And don't get me wrong, it hurt, but I feel fine."

Kevin seems to agree. "Not that I was going for the kill, there, but you're not wrong. It's a good alien, this one."

Ben grumbles. "Yeah, well. Good in a fight, I'm sure, but terribly inconvenient in, like, human society. Everything's so...flammable."

"No joke."

Julie pipes up. "I think I've got it!"

Heatblast turns to see their comparatively tiny girlfriend approaching. Julie is already kinda short, so the Pyronite's seven-feet-and-change height seems gargantuan. "Don't get too close." -Ben warns. "Just the hot air around me could burn you."

Julie winks. "Honor student, remember? I've got a decent understanding of thermodynamics." -she says, then turns to Gwen. "Got a spell that'll protect my skin?"

"I think so." -Gwen nods, then starts chanting in an unrecognizable tongue. Julie's skin turns blue, her hair turns white, and scars like runes pop up all over her body. "Essence of Frost Giant." -Gwen says. "Coldest magical creature there is. I think."

Julie reaches Ben, and confidently reaches for their right hand. The touch hisses like a teapot, but neither of them seem to be in any discomfort. Julie guides their hand to the Omnitrix's symbol on their chest, then takes two of their fingers and traces the hourglass symbol like one might draw infinity. The design immediately turns red and starts flashing, accompanied by a sound similar to an alarm.

It takes about five seconds, but Heatblast's form finally becomes crimson energy, and shrinks back into regular, human Ben with a similarly scarlet flash of light. There's no odd memories or feelings this time; just the knowledge that everything's back to normal, human baseline.

Ben blinks, then yelps as he steps away from the heated ground Heatblast just stood on. Gwen easily removes the enchantment from Julie, who helps steady Ben.

"You alright?" -his girlfriend asks.

"I'm good." -he reassures her. "How'd you know to do that?"

"I'm a quick study." -she winks. "No, really, it's the same way you turn the Plumbers' Badge on and off." -she says, holding up the insignia. "I just figured the Omnitrix came first, and whoever made these was inspired by the watch."

Ben raises an eyebrow. "Plumbers' Badge? Is that what it's called?"

"That was the name of Max's unit within the Nova Corps." -Kevin interjects. "The Plumbers. I can't imagine why they'd choose that name." -he says, voice dripping with sarcasm.

No one really wants the conversation to turn scatological, so they offer no comment. Ben examines the watch, whose faceplate has turned red. "Huh." -he says, tapping the various buttons to no effect. "Guess it needs to recharge."

"Well, that's just inconvenient." -Gwen says, raising an eyebrow. "What if you switch back to human in the middle of a fight?"

Ben shrugs. It is a bit worrying to think about, but he figures he'll just have to quickly win. "It's not like I'll be fighting alone; you guys will be with me! I'll be fine."

"But what if we can't be?" -Gwen asks, worried. "You know how strict my curfews are, and Kevin lives really far from you."

"I live just a couple blocks away." -Julie points out.

Gwen purses her lips. "No offense, Julie, but I don't think you should be anywhere near the action, whatever that may be."

Julie crosses her arms. "Don't patronize me. I know I don't have powers, but it's not like you guys are the Avengers, either. We're teenagers. Powers or no, we probably shouldn't be thinking of fighting crime, or alien invaders. But we're gonna do it anyway, because the vast majority of people won't even bother."

"It's her choice." -Ben tells Gwen. "Believe me, I'm not super excited about the idea either, but getting in her way is only gonna make her angry. Julie doesn't stop."

"Fine. I'm sorry, Julie." -Gwen sighs. "It's still a bad idea, but...as long as you're aware, I guess."

Julie shrugs. "It's alright. We're all in this together, right?"

"Sure thing, Troy Bolton." -Kevin says, teasing.

"Har-har." -she says, then turns to Ben. "Anyway, how long do you think it'll take for the Omnitrix to recharge?"

Ben shakes his head. "No clue. I really should've asked Grandpa to explain how this thing works."

"Oh, don't sell yourself short. You've managed to turn into an entirely different life form! That's no small feat." -Gwen says.

Ben sits on a nearby boulder as thunder strikes in the distance. Odd, since the afternoon sky is perfectly clear. "Maybe, but...well, I honestly just did what felt right. Grandpa said I was 'destined' to wear the Omnitrix; I don't know if that's what he meant, but it definitely felt...familiar, somehow. Like I'd done it before."

Gwen hums. "Maybe you used it in a past life." -she teases.

"Heh, maybe. Though I feel like reincarnation might be a little too out there, even for us."

Kevin hisses. "Oof. That's a jinx, buddy."

"Hostile technology detected." -the badge in Julie's hands pipes up. They all look at it, four pairs of eyes widening in dread. They don't even get the chance to wonder what the Plumber Badge might've detected, as an enormous, tripedal robot breaks free of the treeline and bears down on the quartet.

"Oh, Kevin." -Gwen says, though it's far from his fault, "I wish you hadn't said that."

The machine is maybe forty feet tall, and vaguely resembles a red and maroon humanoid mantis. It has two clawed arms equipped with cannons of some type, two bright insectoid eyes, and three long, slender legs that provide it with eerily silent motion. The robot stops about a hundred feet away, and its crimson eyes light up, bathing them and most of the surrounding area in scarlet.

"Uh...maybe it won't see us if we don't move?" -Ben meekly suggests.

The towering machine buzzes loudly, and extends its arm, shooting them all with a red beam that washes over one of Gwen's hastily erected dome shields. Ben's heart pounds in his chest, and adrenaline kicks in. It feels like slow motion, seeing Julie quickly hand Kevin the Plumber Badge so he can absorb its material, Gwen wincing as she tries to hold the shield together, and his own hand frantically tapping on the Omnitrix's buttons. The fabled watch remains, sadly, unresponsive.

The beam ends, and the drone spends the next few seconds analyzing the situation. Gwen turns the shield into tendrils, which she uses to lash out at the robot's chest - it flinches a little, but the plating is barely dented by an attack Ben's seen pancaking rusted out cars. Kevin roars, charging in full on berserker mode.

That's what he calls it, anyway.

Julie and Ben book it for cover, a taller boulder than the one Ben had sat on. Julie looks scared, but determined. She glances at the Omnitrix as Kevin collides with the robot's right leg, which does bend under the stress. "That thing must've detected the Omnitrix." -she posits. "I can't believe it snuck up on us."

"How do we take it down?"

"I don't think we can." -she says, watching Kevin get swatted away, and Gwen struggle to hold back the drone from charging at the two of them. "We'll just need to hold out and hope the Omnitrix recharges."

Gwen provides a series of platforms for Kevin, who uses them to leap at the robot's head. Unfortunately for him, the extra effort on Gwen's part liberates one of the drone's arms, and it bats the Enhanced teen out of the air before it can make contact. Kevin lands with a heavy thud, and doesn't move afterwards. Gwen tries to fly toward him, but the robot shoots at her, and though she manages to shield herself from the worst of it, the beam singes her shoulder and downs her, too.

Fortunately for the older teens, the robot has no real interest in them, so it doesn't bother finishing them off. Unfortunately, it does want Ben, and takes aim at him and Julie. Ben hopes against hope that the Omnitrix will suddenly turn green.

It does not.

With a roar, and holding her shoulder, Gwen blasts the drone with a beam of solid magenta energy. It carves through its raised arm and part of its chest, throwing off the shot. Ben still feels the rush of painful, hot air, and the smell of ozone.

The robot must have some kind of AI, because it takes the time to aim its remaining cannon at Gwen. The resulting beam clashes against another dome, but Ben can tell from its size that Gwen is already exhausted. Julie surprises the heck out of him with a peck on the cheek. "Love ya." -she exhales, then bolts for a stray piece of debris, and throws it at the robot with all her might.

The small stone pings off the robot's hind leg, which makes it stop the attack. It rumbles with electronic sound and charges at Julie; Ben is ready to take his cue and do the same thing, but just then, the Omnitrix beeps at him.

Ben doesn't even think about it; he pops up the faceplate and slams it back down. There's a merciful lack of memories or flashes during the resulting transformation, and Ben doesn't even stop to wonder what the heck he's become. All he knows is that he's charging - heavy, thundering footsteps and the sound of broken glass accompanying his desperate run. He crashes into the robot's leg just as it's about to smash Julie, who's prone to the ground, the tackle so powerful that the robot actually topples over, massive legs struggling to make sense of its new, horizontal situation.

Diamondhead roars and slams down its cyan, crystalline arms down on the drone's chassis, sparks and metal flying. He tears into the robot with ease, razor-sharp flesh rendering the armored plates useless. He doesn't notice that the moribund machine has lined up a shot, but it doesn't even matter; the red beam refracts into harmless light and dissipating heat upon contact with Diamondhead's inorganic flesh. He's still annoyed, though, and his body responds in turn; his hand turns into a multitude of sharp points, which shoot towards the cannon like bullets, tearing the weapon to pieces.

The confused robot tries to rise, but Ben is way past allowing a fair fight. He reaches for his back, finding a massive spike growing out behind his shoulder, and yanks it free. It immediately regrows, not that he cares, as he leaps up into the air, and stabs its length into the robot's head. Its desperate movements cease, immediately.

Diamondhead stands over the oily carcass, not the least bit winded. He surveys the scene, and finds, to his relief, the three teens slowly walking up to him. Kevin looks none the worse for wear, while Gwen still clutches her injured shoulder, which glows the same color as her magic, for some reason. Julie's pristine white clothes are dirty, and her arms and legs bear scrapes and scratches, but she's otherwise fine.

"Goddamn." -she breathes, smirking like a maniac. Ben hopes it's the hysterics of near-death, and not the joy of a thrill-seeker. You never know, with his friends. "I think I like Diamondhead better than Heatblast."

I hope I conveyed an accurate mix of "How the heck does this alien superweapon work" and "Oh crap, we may have bitten off a bit more than we can chew." Also, I hate-hate-hate the entire plotline of the magitech sword, Ascalon, so instead of dealing with that, I gave it a nod as SWORD's base of operations. Sorry if you like it, but I think it's one of the absolute worst ideas in Alien Force, and the greater Ben 10 canon.

Also, here! Have some "lore" entries! This is how the idea for this story even got started, so I hope you enjoy! They're a mix of headcanons and existing canon, which is a fair assessment of most fics I write.

Heatblast:

The Omnitrix's sample of a Pyronite, from the planet Pyros. Heatblast is a powerful pyrokinetic alien, whose body is composed of igneous minerals, eternally set ablaze. They can shape the plasma that continually emanates from their body, projecting it in the form of tight beams, cones of flame, firebolts, etc. They can also absorb all forms of heat, and propel themself fast enough to enable a facsimile of flight. Their flames may be temporarily diminished by water or a similar dousing substance, but they can't willingly turn them off, which may be damaging to whatever they touch.

Diamondhead:

The Omnitrix's sample of a Petrosapien, from the planet Petropia. Diamondhead is indestructible; as an inorganic life form, his "flesh" is composed of a crystalline material that is impervious to all known forms of conventional damage. He can also regenerate any part of himself, a function that extends to actually creating constructs that can be separated from his body, such as spikes and maces - though the constructs lose their indestructible quality as soon as they're separated from his body. Diamondhead is very heavy, and thus not very agile. He can also be very sharp, which may be harmful to the people around him. Petrosapiens are an extinct race, making Diamondhead the last of his kind.