Since he first graced the silver screen in The Avengers, audiences have adored Loki, the god of mischief. In part, this is due to Loki's development over the course of massive and far-reaching MCU, going from despicable villain to likable anti-hero. Along with that, Loki's deeds have even been considered heroic in some cases.
In the other cases, however, Loki's actions are still seen as being villainous, given his original nature. No amount of heroic actions can make up for everything the brother of Thor, god of lies, the first foe of the Avenger's villainous, has done.
Hero: Aided Thor
As mentioned before, Loki's evil ways slowly turned into a slightly more anti-heroic nature. Time again, Loki would "begrudgingly" set aside his need for domination and death to help people like his brother from another mother, Thor.
Time again, from leading Thor to The Dark World to getting him out of the Grandmaster's contest of champions and even helping his brother escape from Asgard and rescue Jane, Loki has given the word anti-hero new and vibrant meaning. It's something that carried on right up until the trickster god's end.
Villain: Attacked New York
Of course, Loki's misdeeds can't be overlooked. There's a great number to choose from, especially from when he was in The Avengers. From controlling Hawkeye and Erik Selvig to stealing a man's eye, many recall Loki as being the man who attacked New York.
Under the thumb of Thanos, Loki led an invasion via the alien race, the Chitauri, into assaulting and nearly decimating New York City. Fans do argue that Loki may have been controlled by Thanos but nonetheless, he did instigate the invasion, and the mind control is not clearly explicated.
Hero: Saved Asgardians From Hela
It goes without saying that Thor: Ragnorok boosted the trilogy, had some of the series most satisfying moments, some great action sequences, and gave Loki some of his more heroic moments. It brought everything full circle and allowed for Loki to shine more than the other films had allowed, especially when he saved the Asgardians.
Riding in on a ship from the junk planet Sakaar, Loki gave the Asgardians a way out as Hela began to tear Asgard apart and even held the line as they escaped. Not bad for being a member of the Revengers and a former megalomaniac baddie.
Villain: Took Over Asgard And Cast Out Odin
Now, all that said, one could blame the events of Ragnorok on Loki. After all, Hela was imprisoned as long as Odin had his power. Yet, when Loki took over Asgard at the end of Dark World, he cast Odin out into the mortal realm.
By doing so, Loki weakened Odin to the point that when he and Thor found the All-Father, he was at his end and Hela was freed. That, and he turned Asgard on its head, rewrote past events, became its ruler, and made a terrible play.
Hero: Killed Laufey
Being the son of the All-Father is hard enough. Being the son of a frost giant and kidnapped by said All-Father at birth? That's even harder to overcome. In fact, it seems as if Loki favors his Joten heritage, allowing Laufey to enter Asgard as Odin lies in the Odin Sleep and Thor is gone.
However, this all ends up being a ruse, with Loki killing Laufey, his real father. Even though it was personal gain, it was an act that saved Odin, Loki's adopted mother, and Asgard.
Villain: Destroyed Jotenhiem
When all is said and done, Loki's heroic acts in recent years do outweigh the bad. He has proven himself to be more of a hero... in some aspects. Killing Laufey was a heroic move. Turning around and using the Bifrost to destroy Jotenhiem after freezing its guardian, Heimdal, not so much.
In some sick tribute to Odin, Loki, after slaying Laufey, attempted to harness the power of the Bifrost and destroy the Frost Giants' home. This didn't work and Loki fell not just into space but more into the realm of a villain.
Hero: Gave His Life
Despite Thor: The Dark World, being one of the worst MCU films with one of the worst climaxes, it did allow for Loki's evolution to begin. Not as strong as Ragnorok, fans saw Loki's humanity slowly begin to show through, from mourning for Freya to aiding Thor.
It all came to ahead on the Dark World, where, after battling the monstrous Kurse, Loki was fatally wounded. In a last-ditch effort, he killed Kurse, saving Thor and Jane from the beast and sharing a tender moment with his dear brother before "passing on" as a hero.
Villain: Faked His Death
Never trust tricksters. That's rule number one of mythology. Tricksters are always slippery guys. Even though Loki's "death" served as an honorable sacrifice and worthy end, it was but a farce, a trick that allowed Loki to slip away.
Faking his death is a bit of a trend with Loki, honestly. Why is it villainous, though? Because in the instances where Loki faked his death, he turned towards the dark. Thanos and the Chitauri. Conquering Asgard. All his "deaths" led to a darker path.
Hero: Turned Against Thanos
For fans, it's always nice when things go full circle. When misdeeds and crimes are paid off and redemption reigns supreme. When the remaining Asgardians escape fleeing the remains of Asgard are attacked by Thanos, many expect Loki to side with his former boss.
However, Loki turns against Thanos, sicking the Hulk on him, aiding Thor once more after years of having a legendary sibling rivalry, and eventually, even dying by the Mad Titans' hand. It's a noble end for a character who went through so much. Even if it's not really the end, thanks to Disney Plus.
Villain: Stole The Tesseract(Again)
Yes, Loki's confrontation with Thanos was a noble one. Seeing him be a hero, watching his face down his master was amazing. Yet, it should be asked: why did Thanos attack the Asgardians in the first place? Answer: Because Loki had the Tesseract.
Old habits die hard and Loki's habits die the hardest. Once again, Loki stole the Tesseract and led to the remains of Asgard being attacked by Thanos. If only Loki had left the blue rock alone, maybe things would be different for the trickster god.