Some weeks after Igneel's death, inside a dense and isolated forest, a certain black-haired young man with a black robe and a white toga was walking with a firm step. He had come to this place for one purpose, and one purpose only: finding his younger brother.
Being the experienced wizard that he was, he had not missed the magic fluctuation caused by the former Fire Dragon King's passing and definitely not the one linked to the completion of his sibling's dragonification.
As soon as he had felt these events take place, he headed in their direction. To say that he was taken aback by what he found would be an understatement. What used to be a clearing had turned into a devastated wasteland. The ground was covered in ice and as drenched as if rain had been falling for weeks, trees were scorched and various rocks and branches had been thrown all over the place. But his brother was nowhere to be found.
After much trials and tribulation, Zeref had finally managed to locate his brother but he then had to get to him, which wasn't exactly an easy task either considering the terrain he had to cross was restrictive to say the least. The Black Wizard wouldn't usually engage in this type of activity. But he had made a deal with Igneel that he would find Natsu after his death so he would follow through with it. More importantly, he could imagine the mental state his brother was in after both losing his foster father and becoming a dragon on the same day and he didn't want to let him go through that alone, he himself had had to endure the loss of their parents and Natsu himself on his own after all.
Eventually, the black-haired wizard came upon a very deep cave and so dark he couldn't see anything. He was about to step in when he was at last able to make out something from within the cavern. Or rather, something appeared to him from the depths of the cave: two piercing, glowing crimson eyes. That sight would undoubtedly terrify most creatures. Initially, the two orbs of light were approximately at the same height as his head but gradually went up to reach the cave's ceiling. Simultaneously, a loud stomping echoed through the cave and by the time the eyes had reached the cavern's entrance, the silhouette of a dragon could be identified.
On the one hand, Zeref was glad that his little brother chose to stay in his dragon form because it gave him the chance to see it. On the other hand, he would be lying if he said that the being in front of him was not scary looking and, for that matter, he'd probably be scared too right now if it wasn't his sibling, immortal or not. Well, he is a demonic dragon after all, what would you expect?
What Zeref couldn't see was that Natsu was not in a good mood, possibly in the worst mood he had ever been. Not only was the loss of his father still fresh in his mind, but he had also had the unpleasant surprise that dragonification had taken away his abilities to sleep and taste. Now as an Etherious, he didn't need to either sleep or eat since he got everything he needed from the Ethernano in the air. Nevertheless, those were two activities he enjoyed quite a lot, so losing them pissed him off considerably.
"Good to see you again Natsu." he greeted with a small smile.
"What are you doing here Zeref?" was the rather harsh response he received.
"I'm here because I know about Igneel's passing. I'm sorry for your loss."
"You have come all the way here to give me your condolences?" the new Fire Dragon King asked in a sarcastic manner.
"No, but could you please come down? My neck can't take this for very long." Indeed, Zeref's neck had been oriented at an unusual and uncomfortable angle since his brother got at the cave's entrance. Sighing, the Triple Hybrid stepped out of the cavern completely, thus allowing the Black Wizard to get a good look at him. He was then surrounded by a crimson light too intense to see through which gradually shrank and then died down, leaving Natsu in his human form which was thoroughly identical to his appearance before the dragonification had started.
"Thank you." Zeref continued, ignoring or not noticing the irritated look sent his way. "But you're right, I'm also here because I promised Igneel that I'd look for you after his death."
"You two and your schemes…" Natsu growled but was once again ignored.
"And because I know from experience that you shouldn't be alone right now." This caused Natsu's irritation to be replaced by surprise but he remained quiet to let his older brother continue which he did with a sorrowful expression. "When our parents and you died…I was alone, grieving and frankly, I was angry too. Angry at the world for taking my family away and leaving me with nothing. I supposed losing your parents is just the way of the world…and even though I was extremely young when it happened to me…I could live with it. But losing my younger brother whose smile was like no other and could brighten every room…I couldn't accept that. And it is that same refusal that lead me to enroll in the Mildian Magic Academy, spend 15 years doing nothing but try to find ways to revive you and finally get cursed for it."
"Was it worth it?" the pinkette asked while looking at the ground. "All of this just to bring me back, the time pursuing that single goal, the pain, the sacrifice, was it worth it?"
"It's too soon to tell, it could be. But, now that I think about it, if I had to do it all over again, I wouldn't change anything." the Black Wizard responded, growing a small smile and so did his little brother who decided to try to lighten the mood.
"Well, from the looks of it, you need company at least as badly as I do." he joked to which Zeref actually chuckled.
"You might be right about that. So what do you say, want to get out of these woods?"
"Fine with me, let's go." And with that, they started walking towards a less dense portion of the forest.
"Why did you come here in the first place?" Zeref questioned.
"I wanted to go somewhere isolated, where I'd be free to go about my business without risking hurting anybody." Little did he know, Natsu had just given his older brother an idea.
"I see. By the way, if we are going to stay together for a while, there is one thing I will demand of you." the Black Wizard announced in a very serious manner.
"Which is?" Natsu was rather troubled. His brother wasn't one to make any demands so for him to do so now only emphasized the gravity of what he was about to say.
"Do not, under any circumstances, have any physical contact with me for this will automatically and systematically trigger the Curse of Contradiction." the older Dragneel explained, to which he received a nod of confirmation and understanding from the other one. And with that the two walked to leave the forest.
A few hours later, when the night had fallen, the two siblings, in a much less isolated and dense part of the same forest, were sitting on either side of a camp fire that Natsu had made and were catching up on the almost 100 years that separated their last meeting. Well, Zeref didn't really have a lot to tell but he was very interested in hearing about the now-dragon's adventures.
"So, how did you get your other three Dragon Slayer Magics?"
"Igneel found three dragons. I went off to fight them and ate their attacks so that I could obtain their magics." Natsu explained, which made Zeref raise an eyebrow.
"I thought Dragon Slayers could only eat magic of their own element." he stated, though clearly in a questioning way.
"And you were right but, long story short, I invented a Curse Power that allows me to assimilate other magics, though not any magic." the Triple Hybrid added and noticed his interlocutor's eyes widen a bit. The reason for that was that Zeref was surprised at his little brother's resourcefulness. He had to admit that his invention of the Curse Power was brilliant. Possibly even more brilliant than anything he had created himself and there were two reasons for that: the first was that it was a new form of power that relied on a completely different and seemingly endless source of energy than traditional magic, the second was that it allowed Natsu to create curses for pretty much anything, making the possibilities infinite.
Before he had anymore time to dwell on those thoughts or ask more questions, the two were interrupted by the sudden and completely unexpected appearance of a group of 5 people. They were all different except for two things: they were all wielding the exact same wooden staff and they all wore the exact same yellow band with a symbol of a brown bear on their head.
"Well, well, what have we here?" the man standing in the middle of the group mocked.
"Looks like we stumbled upon a couple of lost kids." another snickered which only made the two brothers look at each other briefly, not the least bit offended or frightened but still rose up when the thugs got closer.
"If anything, you look like the lost ones." Natsu retorted which earned him an enraged look from each of the 5 members of the group.
"Don't you know who we are, brat? We are part of the Bear Jaw guild." the leader declared with both anger and pride.
'Who would have thought?' the pinkette thought sarcastically while looking at the band in the leader's hair. "Never heard of it." he said sincerely but was ignored.
"Enough talk! Hand over all your valuables and we just might not hurt you…too much." one of the wanna-be thieves threatened while Natsu was just baffled at their stupidity.
"Look around you. We have nothing for you to take from us." he explained with some exasperation.
"Is that so? Because I spot at least one thing worth our time." the leader said as he pointed at Zeref's pendant. "What is that made of? Silver?" Upon realizing what the mage was referring to, the Black Wizard took an extremely dark look. He didn't really care about the necklace itself but he very much cared about what was inside. It might even be his most prized possession.
When he noticed his brother's death glare towards the leader of the group, Natsu started to get worried. Not for themselves but for the thieves. His brother was a calm and collected person. Angering him wasn't an easy task which was lucky because when he was angry…things could get ugly. "I wouldn't do that if I were you." he warned them.
"Yeah, yeah, whatever you say." a member of Bear Jaw said as he grabbed Zeref by the arm from behind. This action caused Zeref's anger to instantly be replaced by tremendous panic and dread. At the same time, he felt a familiar throbbing pain in his head and a thick black mist was emitted from his body in all directions.
When the mist cleared, Zeref was on his knees and was crying in his hands. He felt bad about killing these people. Sure, they were criminals and deserved to be punished for it but they didn't deserve death. But most of all, with how close to him he was, there was no way Natsu had managed to dodge the Death Predation. And the idea of his little brother being taken away from him again, by his own curse, was filling him with more despair and pain than he had ever felt.
'N-No, I-I can't have l-lost him again…t-this is all my fault, I s-should have told him to s-stay away from me…if I h-had just-' He was pulled out of those thought by hearing something he was persuaded he'd never get to hear again: Natsu's voice.
"I know they didn't deserve this fate but to put yourself in this state…" he trailed off as Zeref took his head out of his hands and stared at him with his eyes almost popping out of their sockets. As if Natsu speaking was the most surprising thing in the world. And to Zeref, it was because he was positive that the Death Predation had hit him and he had never seen anything resist his curse but Natsu had not only survive it but had come out of it completely unharmed.
Without a word, Zeref slowly got off his knees and walked towards his brother who didn't do anything but stare at him with a confused look. When he reached him, Zeref hesitantly poked his brother once and…nothing happened. Natsu, whose gaze had followed Zeref's actions, didn't get enough time to raise it before he was engulfed in a bone-crushing hug and the smell of salt water coming from his brother's tears hit his nose.
Some time later, after some observations, the two discovered that not only was Natsu immune to Zeref's curse and physical contact between the two didn't trigger its activation, but the curse as a whole was a lot less active when they were in close proximity. The reasons for that were unclear but they concluded that the most likely explanation was that since Zeref got cursed because of his attempt to resurrect Natsu, the curse would kill every living being that approached Zeref except the cause of the curse: Natsu himself. Although Natsu wasn't a fan of this kind of sadistic irony, Zeref was over the moon at the possibility to have physical contact with a living being again, especially with his brother. At first, they were only supposed to spent a few days together and then part ways, but this new development changed things and upon noticing how happy it had made his brother, Natsu decided to stick with him longer. The Black Wizard and the Triple Hybrid traveling together, who knows what this could lead to?