After the events of Thor, Asgard flourishes under the rule of Odin, with Thor serving as its greatest champion. Though he has matured since his banishment, Thor still seeks to prove himself worthy of the throne. Unknown to Asgard, Loki survived his fall into the void and lives in secret, watching events unfold from the shadows.
Across the cosmos, gods are being slaughtered by Gorr the God Butcher, a being who wields the dark and living weapon known as All-Black the Necrosword. After losing his family while the gods ignored his prayers, Gorr dedicated himself to destroying all deities. When allied gods of Asgard are found dead, Thor sets out to stop him and frees a captured Kronan warrior named Korg, who joins him.
Gorr eventually attacks Asgard itself, unleashing shadow creatures upon the Golden City. Odin and Thor fight side by side while Loki secretly aids in the defense. In the final battle, Thor chooses to protect his people rather than seek glory, weakening Gorr’s resolve. With Odin’s help and a massive lightning strike, Thor shatters the Necrosword. Freed from its corruption, Gorr dies realizing not all gods are cruel. Asgard survives, and Thor grows closer to becoming the king his people need.