Heather made a tweet asking for a zexal au where [zexal summary spoilers] Yuma goes back in time repeatedly Puella Magi Madoka Magica style to save Ryouga from turning into Nasch and yeah

Didn't work how I intended but oh well.

Warnings; character death.

He hates that it had to come to this.

He doesn't want to stand over a decaying body – if turning to dust and flying away can be considered decaying – but it's still there, Ryouga's closed eyes and soulless body drifting away with the wind. He can't stand it, can't stand that he stood in the way like that, and now he's gone.

It's all because of him.

Yuma drops to his knees, gently stroking at Ryouga's decaying hair. "I'm so sorry Shark, I didn't know! I didn't think it would end like this, I wasn't aware of the consequences!" he's crying, and if Ryouga saw him he knew he'd scoff and get a grip but it doesn't matter what Ryouga thinks anymore because Ryouga's dead and what do you know, it's all Yuma's fault.

He covers his hands, claws at his face and he knows it's pointless, but there's nothing else he can do really – everything is in ruins because of himself, because he had to come, had to stand in the man's way.

[They were friends, how could he not?]

[He just wanted to save him, is all.]

"I'd do anything to get you back." Yuma whimpers as the last of Ryouga flies away, ugly sobs reverberate through the area as he clutches at the air desperately. "Please!" he calls louder, screaming at whatever he can, whoever he can. "Don't let another friend disappear on me!"

He doesn't notice it at first, but the shimmering figure next to him appears deep in thought, crossing his legs midair as he watches the male sob underneath him, mourning the loss of his friend.

"You know;" the figure says, catching Yuma by surprise, though he makes no indication that he's intimidated by the blubbering male underneath him. "It doesn't have to be this way."

"It... doesn't?" Yuma questions, and there's a sudden light in his eyes that makes Astral almost cringe.

[He'll never admit it, but sometimes it hurts to recruit more members to hunt for him. After all, he was suffering too.]

Astral smiles, holding out his hand in offering. "No it doesn't. I can bring your friend back; give you a second chance to work this out."

"Yo-you can?"

"I can." Astral smiles, bringing himself to eye level with the young male. "All I ask is for a little favour in return. Hunt number cards for me, and I will give you another chance to work it out with Ryouga. As many as you need."

Yuma smiles and the hope that resonates from the boy's eyes almost makes Astral's heart break.

[Well, if he had one anyway.]

"I'll do it."

He underestimated how hard it would be. When he made the contract, he was sure, so sure that he could get it right on the second try, but he forgot in the heat of the moment what Ryouga was really like, and even after every single time the timeline was reset and Yuma and Ryouga would meet for the first time, even after he made sure not to let Ryouga break the small green jewel in the key that was now the housing place for his soul; he just couldn't get it right.

Sometimes he would die in the human world, stuck in a duel he could not win and injured to the point that he couldn't continue, or he'd die in the original place he did, Yuma the only one to see and witness his death, over and over again.

Watching Ryouga break his key over and over again never stopped hurting. He'd repeat to himself he's changed, it's just the anger. He lost his parents and he almost lost Rio and it normally works, as long as the gem didn't break, he was fine; it was repairable.

Their bonds ran deeper than Ryouga knew, so at first he was weirded out that Yuma knew so much; stuttering over his words and staring at Yuma in shock when he would slip out a 'how's Rio?' before Ryouga's disclosed that information. But it didn't take long, and as the timeline reset each and every time, he was quicker and quicker to pick up on Yuma's attempts at friendship and was less likely to push the male away.

After a few tries, he's finally made it past the initial fight, Ryouga lives on past possession by a number card. It all looked like it was finally going to work out, then the barians got involved.

It's not long after that Yuma finds another Number Hunter in Kaito, who made his contract to save his little brother from an unknown terminal illness. Kaito scoffs at Yuma's motivations at first, you wasted your life for someone that isn't even family? And sure, hunting numbers is hard but he's got Astral's help, and yeah he gets that he's probably been screwed over badly but he doesn't care, he'd do it again in a heartbeat, if it were to mean that Ryouga were to continue to live on.

Once Kaito hears that, and sees it in action, he loosens up slightly, decides to help Yuma train and hunt numbers together. They lived a lonely life, so it might as well be spent together, right?

It's not long after that Yuma finds the original catalyst for everything; the whole reason he's in the mess in the first place. He originally thinks the culprit would be the leader Durbe, but as he stands along the field in Sargasso, watching Ryouga die from within his reach after losing to Vector, he realizes his true target.

Trying to convince Ryouga that he can't duel Vector is an act that's more difficult that Yuma could ever perceive; he's stubborn and why do I have to duel Durbe? Isn't that the leader's job? Yuma's no leader himself but he's thrown into the position, and eventually he gets his way. He's destroyed because Vector is Shingetsu, oh my god one of Yuma's closest friends is evil, but he reminds himself deep down, yeah its better than Ryouga being dead.

[He can accept when friends walk out of his life, it's only natural.]

[Well, that is when they aren't killed by his own hands.]

Yuma couldn't stop the fact that Ryouga was a Barian himself. It didn't matter to Yuma – who was he to judge? But it was another obstacle, doing his best to help Ryouga through until he reached the point where he knew that he'd be sure that Ryouga's place in the numbers war was long gone.

So, when he acknowledged that Vector was the catalyst, Ryouga knew immediately that he had to go after him, had to make him pay for the suffering he's been through. He claims that it feels like he's been fucked over by Vector at least fifty times, though Yuma has no heart to tell him just how correct he was.

Each timeline is harder, and Yuma notices that each time, Ryouga's death gets more elaborate and he goes slightly more insane in the process. It's far too late when Yuma realizes just how screwed over he's caused not only himself by making the contract, but Ryouga as well. Astral tells him that Ryouga's destined to die in this war, and no matter how often Yuma tries to repeat the system, it's going to end worse and worse.

"Why not just let him die at the first point, where there's so much less suffering?"

Yuma's furious at the thought, though it seems rational to anyone with a lack of emotions. It didn't matter, as much as it hurt to watch Ryouga break his key again and again, as much as it hurt to watch him become possessed by a number again and again, as much as it hurt to watch Ryouga become a Barian and die again and again, Yuma owed Ryouga his life, and damn well if he wasn't going to make sure Ryouga survived this.

[Repeat. He'll repeat again and again, no matter how long it takes.]

It's his hands that accidentally kill him again. Ryouga finally does it, finally beats Vector with his own hands, and Yuma's proud; he's sure he's found the spot, the moment in time where if he survives, he'll survive the war. He realizes far too late that he's relaxed his guard far too early and Ryouga is possessed by Don Thousand and Yuma's forced to pull out all the stops, to pull out his power form in ZEXAL, and it's enough to pull Ryouga free from Don Thousand's grip.

[Too much power, in fact.]

Ryouga dies again.

Yuma can't deny that it's his fault, but despite Astral warning him look, if he dies, we win, but it doesn't matter – he doesn't care at all about winning, he just wants to make sure his friend lives.

So he resets the timeline again.

He speaks to Kaito earlier, much earlier than he should have the last time – Kaito tries to kill him, something about territory? And for some reason, he can't seem to get through to Kaito; that is until Ryouga gets himself involved. Ryouga's soul is gone, only Kaito knows where and Kaito's out for Astral's blood. He's sick of it, sick of this contract but he can't take it back until Yuma's completed his, so Kaito returns Ryouga's soul and decides to help, if only for his brother.

They're an impressive team, the three of them, and Yuma realizes that two just wasn't enough; he needs Kaito's help if he wants to save Ryouga.

Kaito's not there when Ryouga forces his way to the Barian world to avenge his past life and destroy Vector, but he's still helped enormously. The training they did, its finally paid off and Yuma brings ZEXAL out earlier and activates his time powers; he's so much faster, so much stronger and as soon as time resets he's thrown the duel anchor and connected with Vector before Ryouga can even blink.

Ryouga's furious but Yuma understands – he wants to tell him, wants to so badly – cant he see that this isn't normal? This just isn't about revenge – and he finally gets it. The reason that Ryouga dies again and again, it's because his heart is fuelled by revenge and not goodwill, so he continues to suffer a more extraordinary death each time his hate grows.

Yuma defeats Vector, though it's a close call. Ryouga yells at him, what are you doing you idiot! You're so much better than him; don't let him get the upper hand like that! But Yuma's nervous, because he knows what's coming up next, something that neither Vector or Ryouga could possibly have seen.

As Vector falls, Don Thousand in revived and makes a b-line straight for Ryouga's soul. Thanks to his power, Yuma's faster, and he stands his ground in front of Ryouga, protects his soul from the corruption that's instead forced through him. Astral is ejected and all that's left is the boy with the key, he's taken over as Don Thousand forces his way into him. Yuma's stronger than he anticipates, strong enough to call out to Ryouga – Shark, you have to defeat me! – before falling into his grasp.

Ryouga delivers on his end, and delivers the final blow. Don Thousand's swept from Yuma's body and he breathes a sigh of relief, glad that it's finally over.

He makes a critical mistake.

He's forgotten that the damage is real.

He sees the little green shards fly from his key before he feels it; his eyes bulge as the pressure sends him careening through the air. Yuma closes his eyes as he feels everything slip away; it's all worth it because he's sure Ryouga will survive, and he's got Kaito and IV and other friends he's made and its only him, right?

[He'd do it again in a heartbeat, if he had to.]

Ryouga runs to him as his body collides heavily with the ground around them, though there's really no point.

Yuma's dead before he hits the ground.