Just so you know, this is a mixture of Marvel canon, Norse mythology, and my own ideas. Different parts will make sense to different people who read this. Just so you don't get confused or mad at me for screwing with it, you've been warned that I have, in fact, screwed with it. Creative license, or whatever.
I don't own much, not that that helps anything legally. I'm also my own editor and everything, so any problems are mine.
'So, without further gilding the lily and with no more ado, I give to you,' the story!
Life makes sense to Loki.
In Loki's eyes, everything has a place. His wife's place is right behind him, as she must be protected, but Sigyn does not have to love him. It is a fine thing that she does not have to, because she certainly does not, and never will. His place is in Asgard, as a prince that will never be a king and must be content as such. His eldest son's place is with him, at all times, just in case something goes wrong, because Nari is the one of the only worthwhile beings, in Loki's eyes. His youngest son's place is behind his eldest, because that is the place where Vali can be safe. His brother's place is immediately beside him, so that he may keep an eye on his impulsive brother and make absolutely sure that Thor is safe. Loki's place is protecting them all for as long as he can, as best as he can, because he is sure that they cannot protect themselves.
Loki does not belong.
Loki is told that he is a child of two worlds, but, in his mind, he is a child of none. He may have been born to Laufey, but his birth father abandoned him. He has so sickly and small that he was left to die. Laufey did not care enough to protect the prince, his son, and he was abandoned. Odin took him, but it was far from out of the goodness of his heart. Odin took him so that he may someday unite the two lands. He was raised as a pawn, and was never a true child of either realm. He despises this of himself, that he was never honestly worth enough to belong. He wished with all his might that someone wished for him to be there, but he knew the truth. Loki knew that he was not wanted.
Loki hates himself.
With every fiber of his being, Loki hates himself. He did not belong anywhere. He was not wanted anywhere. His entire mind was filled with hatred for himself. He knows that he is filled with a darkness, with an evil that will not subside. He cannot help but act on it, and he hates that. He looks into his sons' eyes and he sees the echo of fear. He looks into Sigyn's eyes and feels the chill of indifference. He looks into Thor's eyes and feels the ache of loss. He looks into the looking glass, into his own eyes, and he feels the emptiness of himself. The anger and hate is a roar in the back of his mind, constant and sharp, and he will never be free.
Loki longs to die.
Every second of every day is a countdown towards his death. He cares not if he dies at the end of everything, or if he dies at the hand of a son, of a brother. He cares not if he dies of sickness or disease, or if he dies by his own hand. He just drags himself through his life because death is the light at the end of the tunnel. If life is a challenge, death is a reward. Dying will be the sweetest release that Loki has ever had, and he wants it. He stares at the weapons laying around him and contemplates which could kill him the fastest. He watches the warriors and decides which he could anger the easiest. He trains his sons to never trust a single soul, because if they trust no one, they will never trust him. If his sons do not trust him, then it will not be difficult to convince them to kill him. Loki would rather die at the hands of his sons than at the hands of anyone else.
Loki is relieved.
When Nari is killed, Loki blames only himself. It is his evil that caused Vali to become the monster, and it will never be the fault of his sons. He deserves to be wrapped in his own son's entrails, because he has earned his fate. This fate is worth than death, and he loves the suffering. Every agonizing second that his son's blood drips onto him, he smiles. He knows that this is the grand prize. This is greater than death. This is what he wants, because death would be too easy. Death would be far, far too easy, and he deserves only the worst. He deserves the most difficult punishment, because he committed the most fiendish crimes. His murders have earned him this fate.
Death makes sense to Loki.
He swallows the blow of the fires and the destruction inside of his very soul. The burn rips through his very being and he laughs into it. He enjoys every damned second, because this is what he has been waiting his entire life for. This is death, and it is sweet. His blue eyes are consumed by red, and he is unsure whether it is fire, or blood, or simply his true color returning to him in his last moments. His skin flickers between blue and patterned, and pale and scarred. He lifts his hands to wrap around his chest, a final embrace. His son screams at him, Thor is trying to touch him, and Loki ignores every sound but his own joyful laughing. He tilts his head up and watches the tunnel of flames consume the sky in his eyes. The last thing he sees is the lick of flames soaring into his mind, and then it is all dark. He is blind and deaf, and the fire swallows him now. Every moment of his death is savored, worshipped. He falls to his knees and crumbles to ash. The last thought in his head is relieved. He is so relieved that someone has finally taken mercy on him, even if he did not deserve this final grace. He laughs and his head collapses. He smiles and his heart burns. He breathes and his soul escapes. He dies and the realms sing.