"I'd have to try terribly hard to be that terrible"
— Conversation between kid Loki and Thor.
Originally an Anthology Comic by Atlas Comics which later became Marvel Comics, it is known for debuting The Mighty Thor, in issue #83 (August, 1962), by Stan Lee and Jack Kirby. The series would regularly feature Thor there until issue #125 (February, 1966). With issue #126 (March, 1966), the comic was renamed The Mighty Thor.It has been revived as a separate title a few times since then from 1972 to 1975 as an Anthology Comic, and again in the 1990s replacing Thor's book with issue #503, following the Heroes Reborn relaunch of key Marvel properties from 1996 to 1998. Finally the most recent revival of the series was during the Fear Itself event and relaunch of Thor's book as The Mighty Thor in 2010 starting with issue 622.From issues 622-645, the main character changed from Thor to his newly-reincarnated brother, Loki. Issue 646 starts a new arc focusing on Lady Sif. It lasted to Issue 655.
Breaking the Fourth Wall: At one point, Loki grabs the narration boxes and tears them up but this is actually a subversion, as later it's revealed that the narrator of the story is an actual character in-story.
Loki also directly addresses the audience a few times in the last chapter.
Brick Joke: Early in the run, there is a bit of narration that refers to Leah as Hela's left hand, in contrast to Tyr being Hela's right. Turns out that she is literally Hela's hand, although the artists never seem to agree on whether it's her left or her right
In Journey Into Mystery 625, Loki is dealing with the aftermath of bringing some dire news to Hela. When he recives worse news, he reports to her handmaiden Leah, who tells him he "already brought" dire news, so he corrects himself with "Dire-er news!" Almost at the end of the issue, he runs up to Hela and Mephisto, who are having Parley, and loudly declares "DIRE-EST NEWS!" and Hela looks exasperated.
Central Theme: Change is good. The new is good. But this is a single run in a single series that is part of a huge mainstream comic continuity, so it's never going to last.
Foil: Loki identifies quite a bit with the hel-puppy that he names Thori since they're both supposedly unalterably evil beings. The difference between them is Thori loves being what he is and happily reverts to form the first chance he gets, while Loki does everything he can to avoid his fate
Gainax Ending: Gillen had to post an explanation of what had happened in the ending on his tumblr, because at least half the fanbase didn't understand what had just occurred.
Gambit Pileup: There are a variety of different factions competing against one another in Journey into Mystery however this is notable as probably being one of the few cases where a character competes against HIMSELF
Hope Spot: At the end of the Everything Burns crossover with The Mighty Thor, they've succeeded in defeating Surtur, Loki's been definitively given Thor's trust, the Nine Realms know that it was Loki who saved them, Leah's back (sort of) and they're all going to live happily ever after. JUST KIDDING Mephisto has the Fear Crown and Loki has to annihilate himself to get rid of it.
Loki's "Damn me" on the final page could be seen as a hope spot. As far as character development goes, being able to admit that he is at fault is absolutely huge for Loki and it indicates that Kid Loki's final words have achieved something significant. Unfortunately he quickly follows it up with a more standard "Damn you all" indicating a return to his old self.
the Leah revealed at the end of The Mighty Thor 19 was the one Loki wrote into the Serpent's story
Leah would become Hela
Ikol only existed in Loki's head
Literal Split Personality: Kid Loki is Loki without all the baggage of his past, being without any memories of his previous life. Ikol is the remnant of the past Loki, with all of the baggage and memories.
This is subverted when it's revealed that Ikol doesn't actually exist outside of Loki's mind
Lying Creator: As of right now, it looks like Kieron Gillen (the writer) lied when he said that the Loki in the upcoming run of The Young Avengers is still 13-14 years old
Magpies as Portents: The magpie rhyme is an overarching theme - the run begins with a group of magpies on a quest through the Nine Realms after old Loki's death, and the remnant of evil Loki takes the form of a magpie to follow Loki around.
Memory Gambit: Old!Loki's reason for creating Kid!Loki via his resurrection without his memories in the first place. He sets himself up with a new, baggage-free life in order to regain trust among those that wouldn't before for one of his own schemes that would allow 'him' to change, all the while setting things up to create a situation that would force Kid!Loki to take on his personality. Kid!Loki claims victory in that he "dies" knowing he did change, while Old!Loki setting up this scheme in the first place proves he never will.
Wham Episode: Issue 641 Leah's goodbye and Surtur being revealed behind the Manchester Gods that Loki just helped.
Issue 643 Herald!Leah is revealed to be the Leah that Loki wrote into the Serpent's story, and then Loki tells her that he's sick of being hated and mistrusted by the Asgardians, that he resents Thor for bringing him back to them, that he honestly is upset about what happened to Leah and wants to help her, and that he wants to let everyone burn in Surtur's fires. And then he dumps Thor into a lake of lava. It turned out later he hadn't really switched sides, but he still dumped Thor in the lava and (probably) wasn't even lying about most of what he told her.
Wham Line: When the Herald of Surtur reveals their identity to the readers. "Leah of Hel knows Loki's character better than her own."
And a few issues later, from the same person no less: "Ikol. The bird. You know he doesn't exist outside your head."
With Friends Like These...: Loki and Leah. In fact, he once figured out when someone was impersonating her due to the fake Leah being too nice.
Trickster Mentor: Aerndis the witch, her 'Berserker' spell only loosened Sif's normal restraints and everything was just meant to show Sif that the defenders of Asgard were not weaker then those of the past, enemies had just become craftier.
Unresolved Sexual Tension: The summaries for the Seed of Destruction arc indicate that this will occur between Sif and Beta Ray Bill.
Anchored Ship: Sif still has some feelings for Bill, and while they've acknowledged their past relationship, he's astutely devoted to Ti Asha Ra. Sif helps reunite the couple after she saves Lady Gaea from a mysterious infection.