From films, to comics, to fan art, and slash fiction, Loki--or at least Marvel's many interpretations of the Norse god--is here to stay. The character has survived the better part of a decade in Disney's cinematic hands. And the house of mouse's rogues gallery, Marvel-related or otherwise, isn't known for its long average lifespan.
There's good reason for the tricksters god's longevity, too. Tom Hiddleston's magnetism doesn't hurt the character's onscreen chances, and his role in forming The Avengers ties him intrinsically to Marvel in ways most villains can't boast, but it's the very nature of mainstream comics that makes Odin's prodigal ward so unique among comics. Specifically: they just can't stop changing with the times.
Of course, neither do most comic book mainstays. Frank Castle has gone from Vietnam vet to a Middle Eastern campaigner. Magneto switches from bad guy to good every other week and, according to canon, Dazzler never discoed (heresy, I say). Although none of these characters have gone through their chronological paces as gracefully as Loki. Because while all comic characters must change with the decades, the anthropomorphic personification of lying is best positioned to take advantage of it.
You can track the genderfluid deity's personal journey back literal centuries, but his exploitation of the Marvel U's sliding timescale truly began in Marvel's Siege event. An "heroic" self-sacrifice left the character dead and, like all mainstream comic characters, in need of an inevitable resurrection. That came in the form of Kieron Gillen's "Kid Loki": a younger, reincarnated character with a clean slate. The original bad guy became... good.
Then he was bad again. Then good again? And now it's not so clear. Which, increasingly, seems like entirely the point. Gillen's tragic Journey into Mystery run set the stage (with bad Loki ousting his own reincarnation) while the following Young Avengers series twisted the knife. So contrite was Loki at murdering his own, more innocent self that he began turning heroic again out of sheer guilt.
But starting with Al Ewing and Lee Garbett's Loki: Agent of Asgard, the title character actually recognized the constantly shifting nature and logic that otherwise plague his counterparts. A parliament of past, dead, and possibly imaginary Lokis conspired to make the god even more penitential. Meanwhile, an evil Loki from the future trying to contort his younger self back towards wickedness. Loki was literally his own primary antagonist and most vocal detractor.
If that sounds like a lot to keep track of; it is. That's just comics--and few "big" Marvel series play with surrealism like the Asgard stuff. Common or not, somebody needed to clean the slate yet again. That came in the form of 2015's Secret Wars, which kinda-sorta restarted Marvel Comics continuity all over the place.
Now, Loki is sort of a recurring agent of chaos: a kind of antihero who does bad things for self-proclaimed good reasons. Yet that new status quo can't erase all the many steps we took to get there. He's been bad, he's been good, he's been male, female, a furry, and most recently Sorcerer Supreme. But through it all he's also been the god of lies. In that way, Loki's constantly shifting nature doesn't just seem true to form. It's absolutely necessarily to make the character, ironically, believable.
It goes beyond the gimmicks and general housekeeping comics require, or otherwise foist on readers. When Captain America became a Nazi, for instance, there weren't two comic readers in the world who actually believed he'd stay evil--or ever was in the first place. When Wolverine (or any character popular enough to have several multimillion-dollar movies) "dies," everyone knows it's only for a couple of years. Tops.
When Loki says he's bad, good, or something in between, however, we have cause to believe (and disbelieve) him. Which is damn good characterization in a medium beset by forgone conclusions.
The aforementioned Sorcerer Supreme story, courtesy of Donny Cates and Gabriel Hernandez Walta, offers one of my personal favorite examples of the character's modern lineage. Other such stories have shown Loki's coiling personality with explosive heroism and devilish plots. Cates and Walta, however, boiled the whole effect down to Doctor Strange's pet basset hound.
A petty duel between the two magicians drives the dog, Bats, to a canine heart attack. Of course, killing animals is basically shorthand for evil, and Loki was clearly (and eventually publicly) up to something at the time. Yet Loki's seemingly heartfelt remorse at the dog's death left me... genuinely uncertain--wrapped up in the drama in a way I haven't felt since tearing through the believably teenaged angst of Ultimate Spider-Man during my own high school career.
Credit where it's due to Cates' dialogue (and that's a lot), but such character moments in comics are only that potent when they're part of a proven, sometimes tarnished, ever-present legacy. I choke up when Superman promises hope because, or when Captain America stands up for someone weaker than himself, because of what those gestalt legacies represent--not just the shining moments themselves among what is, admittedly, usually mediocre storytelling.
For me, the death of one very good boy has Loki was the tipping point to bring him into that pantheon of characters. I doubt I can trust him to keep it that way forever, of course, but isn't that the point?