Algrim the Strong is the secondary antagonist of Thor: The Dark World and was one of the Dark Elves of Svartalfheim who became Kurse, an enemy of Thor.
Thor: The Dark World
Algrim is Malekith’s trusted and loyal lieutenant. He fought at Malekith's side during the initial war with Asgard thousands of years ago, but now their time is running out. Algrim is called upon to make the ultimate sacrifice and is transformed into the monstrous Kurse. With a new and terrifying power, Kurse seeks to destroy Thor and Asgard in preparation for Malekith's arrival.
While Malekith and Frigga talking, Algrim walks from behind and stabs Frigga, because Malekith knew she would not say where it was Jane. Seeing his mother dead, Thor attacks Malekith with his Mjolnir, and he was about to defeat him, Algrim jumps and defends its leader. Later, Algrim is seen alongside other dark elves waiting for the recovery of their leader, Malekith.
After supposedly Loki betrays Thor, Algrim tells Malekith that Loki is an enemy of Asgard like them. After discovering it was a lie, Algrim fight against Thor, when Algrim is about to kill Thor, Loki stabs him but this was not effective and stabs Loki.
He was later killed by Loki Laufeyson as Loki said, "See you in Hell, monster!"