Tony, it turned out, wasn't the only casualty that day.
Jut before Iron Man gained the gauntlet and brought Thanos army to nothing, Loki was locked in hand to hand combat with a magic-wielder of the Black Order. Neither of them could find space in the duel to wield their power, so it was a brutish fight of blades and blows. The creature had nearly overpowered Loki, beating him down with a bashing like an undertow - he just could not find the way out from underneath. Just as his oppressor found the slightest opening and was about to use a weapon to deal Loki what would have been (at the least) some seriously debilitating punishment, Fenrir was there and cracked the creature's skull with his sharp hooves. The great black stallion whinnied at Loki even as he charged back into the fray.
Loki stood quickly to make sure his opponent was incapacitated, but a sudden muting of the surrounding clash made him turn his back on the thing of the Black Order. He saw, just on the outskirts of Thanos' raging army, a swirl of dust. It was like a breath of wind had swirled the dirt up and, liking the way it whirled, decided to rage into a tempest.
Before Loki's very eyes, the Leviathans, the Outriders, the Sakaarans, and all manner of Chitauri were disappearing into dust! He saw Fenrir wheel and begin to trot joyously back to him.
They had done it then! They had wrested the gauntlet from Thanos and willed his army away! Loki choked on a sudden, sobbing laugh as relief washed over him. The thought came to him that he could stop fighting soon and gain something of his quieter self back.
So short lived was that moment it might as well have been an iridium flare - the millisecond glint of light reflected from metal wings in space.
There was suddenly a blade at his throat, the stink of the Black Order creature in his nostrils. The thing was already dissolving into dust, but a flick of its wrist would end Loki's life.
Instead, it slipped momentarily into Loki's mind, found his deepest fear, and laughed. Then, with one word and a twist of his fingers before he blew away, he did that which would lead to breaking Loki heart and soul . The swirl of magic that had been unleashed was not directed at the Asgardian in his grasp, but at the great stallion running toward them.
Loki stumbled forward once the grasp on him was gone, but it was too late. A strange haze enveloped Fenrir. His whole being warped, twisted in on itself, contracted and then burst outward into a new shape. In running, his forward momentum had not slowed. He hit the ground hard, tumbling over and over. By the time Loki started to move, Fenrir was already screaming.
This awful thing, this idea that had buried itself deep in Loki's brain, this dark worrisome horror that the Black Order creature found had just been a passing comment in a conversation. Loki couldn't even remember with whom (had it been Tony?) he'd been talking.
"Why don't you study up on it? Get with Strange? Make him human ... er ... Asgardian ... whatever you want to call it?"
There had been a warm wall to lean on, a lovely evening, a good drink to quaff while watching Fenrir gallop about below. The horse would occasionally stop beneath Loki's vantage point and toss his head in greeting, then return to frolicking like a colt.
Loki had felt a wave of cold wash over him at the suggestion. It was all he could do to keep from turning Jotenhiem blue and force himself to chuckle.
"No, I think not," he'd said simply. "Going from a mind like we have to that of a horse is hard enough on one's sanity ... and I should know." He raised his eyebrows significantly and took a drink. "I can't imagine what transferring even an intelligent animal mind like Fenrir into a man's body would do. Insanity would probably be the least of it."
"So, you think he's happy the way he is?" It was a softly sarcastic question, an amusing one as they watched the stallion gambol about.
Loki shook off the last of the chill that had invaded his person. "Definitely."
Now, he caught Frenrir up, wrapped his arms around the muscular torso, felt the heaving chest against this own as the young man he held panted in panic. Fingers clawed at his back and he could hear a grinding and cracking as Frenrir clenched his jaw against the madness of strange sensations and new awareness. Loki fumbled at his side and found the baselard in its sheath. He pulled it out with a jerk and, using almost the same motion, plunged it into Fenrir's side beneath his raised arm. It slid neatly between his ribs and pierced his heart which was beating so hard that it ruptured upon contact with the blade. Fenrir's body only shuddered slightly in shock before falling slack with death in Loki's arms.
They found Loki kneeling by the body, eyes fixed on the empty sky. Who was this, they asked? The green eyes were dull with death, the dark hair long and matted, the face a frozen mask of distress, but it eerily looked like Loki himself.
Loki lied. The only way he could go on was to know, through and through, that he had been merciful - that Fenrir had actually died in battle and that youth laying in the blood-soaked grass was no more his son than Odin was Loki's father.
And so again, he was alone.
Do not weep for those who have found Death's embrace early, for they weep for us that linger on in this mortal world of pain.”
― Stewart Stafford