Loki
From Norse mythology to Marvel: Loki Laufeyson, the god of cunning! In the MCU, Odin's foster son and Thor's adopted brother deviates somewhat from the original, but honestly: who cares? Tom Hiddleston's portrayal is just too brilliant!
Earth's Mightiest Villains
In the comic book event Acts of Vengeance, Loki forms the Prime Movers, a group of supervillains consisting of Doctor Doom, Magneto, Kingpin, Wizard, Mandarin and Red Skull. (Apocalypse, Cobra and Mad Thinker declined with thanks.) The squad's goal was, logically, to destroy the Avengers. Why Loki doesn't appear in the list? Because, typically, he was just the initiator in the background. Disguised as a nondescript man in a white suit, he made each of the villains think the Prime Movers were his own idea. In the end, as expected, the project failed due to the sheer excess of superiority complexes and mutual dislike, for example between Magneto and Red Skull. Still, nice try, Loki!
Loki: From villain to fan favourite
.He brought the Frost Giants to Asgard, tried to destroy Jotunheim and reduced New York to rubble. Quite a few innocent people he has on his conscience and he made more than one attempt to add the death of his brother Thor to that inglorious list. And yet Loki is an absolute fan favourite! How the hell can that be?
Ripping off the villain label
.Even in the first two MCU phases, critics, pop culture writers and fans loved nothing better than to discuss the so-called "Villain Problem". Not even wrongly, because the vast majority of Marvel villains were little more than colourless decals of a threat. They usually had little exciting or incomprehensible motives, were all too often simply the antithesis of the respective hero and, above all, they never lasted longer than one film. Not so Loki! Although he was a privileged Asgardian prince, we could empathise with him. Understand why he does what he does. Which, aside from Tom Hiddleston's performance (more on that in a moment), is for one main reason: Marvel let it happen.
Instead of dumping Loki into the MCU's villain trash heap, somewhere between Iron Monger, Kaecilius, Yellowjacket and Aldrich Killian, Loki was allowed to keep popping up. Which gave Hiddleston the opportunity to keep adding layers to his inherently deep character in the first place. He was allowed to play the hero more than once, to provide comic relief, to make fun of his brother. In short, he was allowed to bring Loki to life. To a fully-fledged character that does justice to the comic book template. And thus became more popular than most of the Captain America brand of shining heroes. (No, we have nothing against Captain America!)
Before anyone yells "THANOS" now: Yes, Josh Brolin's Mad Titan is one of the few (but definitely present) exceptions. He's been teased for years and showed impressively in Avengers: Infinity War and Avengers: Endgame how to build a big threat without sacrificing comprehensible motives. But for all the depth, in the end Thanos was still primarily the "bad guy". Loki, on the other hand, had long since torn off the label of antagonist by that point, transcending the role of villain.
The true hero of Asgard
Another major point in favour of Loki's appeal is, sure, Tom Hidleston. What can we say, the guy is just phenomenally handsome, talented and charming. When the first posters of Hiddleston as Loki were released, he looked like he had jumped straight out of the comics. The fact that Hiddleston and Chris Hemsworth simply have chemistry and are hugely entertaining doesn't hurt either. But in the end, it's not Tom's charisma, the great costumes or the good relationship with fellow actors that are the most important reasons why Loki is among the best MCU characters.
The character Loki was written to exploit but also counter the typical tropes for villains. In a sense, he plays with the audience's expectations. Most importantly, Loki is not the Thanos-brand diabolical supervillain. Yes, his deeds are terrible, no question. But never so terrible that we wouldn't forgive him. Loki is always felt to be on the cusp of redemption. Shows remorse, whether sincere or not, and when the situation calls for it, just takes the right side after all. And because he is so difficult to read, we never lose interest in him. The fact that his motivations, as mentioned above, remain comprehensible, helps additionally.
Tom Hiddleston once said that every villain believes he is the hero of his story. That fits here too. Loki sees himself as the true hero of Asgard. Which is kind of true. In a way. Because after Loki faked his own death at the end of Thor: The Dark World and, in the guise of his foster father Odin, ascended the throne of Asgard, he proved himself a capable leader. Leaving aside for a moment the huge golden statue of Loki that he had erected, we must acknowledge: Asgard really flourished under his reign. Just look at how happy the people are in Thor: Ragnarok! It's worth mentioning.
More than the god of mischief
.That Loki is more than just some run-of-the-mill throwaway villain can be seen elsewhere. There's just an incredible amount of awesome Loki merch. Which perhaps more than anything else shows how popular the character really is. And at Elbenwald you get pretty much everything when it comes to Loki merchandise: Lots of funko pop figures, Loki-caps, Loki-T-shirts and -mugs, but also Loki-hoodies or Loki-socks. Some of the Loki fan merchandise relates to his film appearances, some to the Disney+ series Loki. And since the latter will continue in the future, we're sure there will always be new stuff coming in when it comes to Loki merchandise. Whereby, between us: even if the series were cancelled, we could never be sure that Loki wouldn't return anyway. The god of mischief has too much experience with faking deaths.