Milestone: Killed by Loki
Algrim is Odin's trusted advisor and counselor, a survivor of the Dark Elves and a steadfast friend to the young princes, the one who checks on Thor after each quarrel with his father and keeps the boy's secrets. Beneath his loyalty runs a deep and buried grief. His people were destroyed in Jotunheim, wiped out after they turned to Surtur and his fire sword for survival in their war against the Frost Giants, only for Odin to strike Surtur down and seal the Dark Elves' doom. When Thor recovers the Sword of Surtur, Odin sends Algrim to bring the boys safely home.
The quest becomes the undoing of the friend the princes trusted. Taking the fire sword from Thor, Algrim reveals the vengeance he has nursed for years, blaming Odin for abandoning his people to extinction. He turns the weapon on the Allfather, striking him down gravely, and marches to lay Asgard itself in ashes. Though Thor cannot forget the many years Algrim was his family even as he cannot forgive the treachery. His betrayal ends at Loki's hand, the younger prince killing him to stop the slaughter,