Overexertion
Wanda Maximoff was easily Loki's favourite person in this planet they now called home. She was incredibly powerful, and yet nobody seemed to realise it, or trust her with those powers. And Wanda ignored them all, all those people saying she should be locked up or stripped of her powers, no, she knew that those powers, that magic that she was able to do was part of her now, and the world would have to learn to trust her with it.
He'd been teaching her some ways of controlling and maximizing or minimizing the effect of her telekinesis and other abilities, like manipulating people's memories and getting into their head. She had a natural talent for those things, and had simply needed someone who knew a bit about spells and extra-worldly powers to guide her to excel at it. And excel she did, and had taken Loki as her guide, and he was proud of what they had achieved together.
Not only now she able to control her abilities more, she was able to focus them, stretch them, expand them or hide them, if it was needed. She had exercised her natural gift for magic like a muscle and now was in complete control of all of the many things she could do. And she was, apart from powerful, very grateful.
“I couldn't have done this without you.”
She said a lot of things like those, and always thanked him for teaching her, for being patient with her, for trusting her with what she could do, and never look down on her because she was young, or a woman, or a foreigner. Loki treated her like an equal, which was something considering that he was a god and a prince from outer space who disliked most humans. But he'd used some of his precious time to teach her, and encourage and tell her that she was a godess and that her magic was a gift, not a curse.
She made her feel at ease with what and who she was, in a world that was always trying to make her be less. And they had both started working against the Avengers and now were with them, and she knew that there would be people who would always suspect them and their witchy powers. But Loki had trusted Wanda and taken her under his wing, and Wanda tried to do the same.
Defended him in discussions, included him when somebody decided to keep him out of the loop, protected him when she could. She looked up to him, in a way nobody in Asgard ever had. It was really sweet of her (Loki had spent so long without a single friend, every little gesture mattered to him) and he wanted to do something for her, something special. What use is being friends with a god if you don't get godly advantages?
Besides, her birthday was coming up, and he had always loved big dramatic gestures. Although this one may be a teeny tiny bit more difficult than usual.
“Wanda, I know there's something you've always wanted, and I want to give it to you, as a thank you for being by my side, for all you've done for me, and with me. But it's.... it can be dangerous. I wanted to ask you before trying.”
She frowned.
“Something I want....? Does this have to do with Vision....?”
“Not with Vision, but with your brother.”
“Pietro.”
“I learned that his body was frozen, much like the Captain and Barnes were, kept in the ice.”
“What are you saying, Loki?”
“I've died before, Wanda, and came back. There are things that no Midgardian or Asgardian know that I do. I could try and bring him back.”
“You... you wouldn't joke about this.”
“No, joke, Wanda. If you want it, it will be your very own god-sized birthday present.”
Of course she wanted that! But it was too beautiful to be true.
“What's the catch? There's always a cost for these things.”
Loki sighed.
“The energy required for the process is.... a lot, really, enough to drain even the likes of me, much more a mere mortal like yourself. But together, and with your new-found ability to store large quantities of magical energy, we could pull it off, Wanda. You'd have your brother back.”
There was more than that, and Loki knew it. But he also knew that Pietro's absence haunted each and every of the days of his enthusiastic apprentice, and he knew he could help, even if things weren't going to be as pretty as he was painting them.
Wanda psyched, but afraid to get her hopes up. They needed to do this clandestinely and then pretend they didn't know what had happened, or else they would even more suspicious of Loki than they already were, or worse, using him to bring back whoever they wanted. No, this needed to be kept between them, if at all possible.
Loki had warned that she would be feel light headed after they finished, and very tried for many days. It didn't matter. If they got Pietro back... everything would be worth it. So they did it, they got his body and started the long magical operations they had been studying for a month to bring him back as he should be, as he was. Whole.
So that Wanda could be whole again.
It was overwhelming, the amount of magic and energy they conjured up, almost enough to lose one's head. But Wanda stayed focus, always remembering her goal. The stakes were high, she needed to deliver perfectly. So did Loki. He was glad to finally let his magic go rampant, build up and create something of epic proportions, without anyone telling him to stop, to control himself, that he was scaring people.
No, now Loki got the chance to use his magic at the maximum of its strength, and for a good reason. But it was pulling him, eating him – and it would take her too, if he wasn't careful. And all their work would be nothing and he would be the one that caused her her to be lost. No, he wouldn't let it happen. Not to her.
Suddenly, it was over, and Wanda saw in amazement how her brother opened his eyes and recognised her.
“Hey, little sister. How long have I been sleeping? It feels like a million years.”
And so Wanda hugged him, embraced him for all those days she couldn't, and she was crying, but it was ok, because her brother was back, and nothing else in the world was important. They talked a bit, they hugged and then Wanda remembered that they weren't alone in the room.
“Pietro, this is Loki, he allowed....No, no, no, no no!”
Loki was on the floor, paler than he'd ever seen him, blood coming out of his mouth and eyes. Unconscious.
“Loki!”
She went out to him, tried to wake him up, and so did Pietro. If this person was important to her sister he was important to him, too.
His breathing was too slow, his heart beat nearly non-existent. But he managed to open his eyes long enough to see that they had succeeded. Wanda had her brother back, all thanks to their combined magic. In his head, Loki had shut the mouth of every Asgardian who had called him weak for doing spells and enchantment. He felt the most powerful being alive, even if he had the energy level of a dying old man.
“Happy birthday.” He whispered in Wanda's direction, and passed out.
Pietro took him and in a matter of seconds (oh how good it was to have him back) Loki was in Tony Stark's med wing's expert care.
Loki was barely clinging to life, his blood sugar and breathing rates in the absolute minimum compatible with life. As it happened, Wanda realised that she wasn't feeling tired as she was supposed to, as she'd said she'd be. That idiot had been afraid for her, and had taken the brunt of the energetic cost of what they were doing, and it had nearly cost him his life.
That overdramatic fool.
It took a lot of medicine and some magic to stabilize Loki again, get some colour in him, some energy. He flatlined a couple of times, but was thankfully brought back with seemingly no permanent damage. Still, it would take some time for him to be back where he was, health wise. He'd never been the strongest guy, and almost dying so many times had taken its toll.
He stayed unconscious for a whole ten days, and Wanda had her birthday party in the room where he was recovering. She was kind of angry that he risked himself like that, but once she knew that he was out of danger, she was happy.
She wouldn't have been able to live with herself if Loki had died to bring Pietro back, but having them both....
She lay on Loki's bed, next to him, watching his still pale and sickly form, watching him sleep.
“Now what the hell am I going to do for your birthday, huh?”