Gorr the God Butcher is already Thor's worst villain ahead of Thor: Love and Thunder because of Thanos. Chris Hemsworth's Thor is continuing his arc post-Infinity Saga in the Taika Waititi-directed movie. In Thor: Love and Thunder, the titular God of Thunder is set to face off against Gorr the God Butcher, played by Christian Bale. Marvel Studios has kept details about the villain scant, but with the limited information known about the character, he appears to be the most dangerous adversary Thor would face.
Marvel is going bigger and bolder with Thor: Love and Thunder on the heels of Thor: Ragnarok's success. Aside from the God of Thunder himself, the Thor sequel will also see Jane Foster (Natalie Portman) returning to the MCU wielding the hammer Mjölnir as Mighty Thor. Together with Valkyrie (Tessa Thompson), they are set to square off against Gorr the God Butcher, who harbors a grudge against gods and wants to exact revenge against them. For his and the rest of Asgard's sake, Thor needs to unretire and return to his fighting days to stop his newest foe.
Disney and Marvel Studios' marketing campaign for Thor: Love and Thunder barely reveals anything about Gorr the God Butcher. Despite this, he is already Thor's worst villain because of the God of Thunder's previous encounter with Thanos. In Avengers: Endgame, it was still a traumatic experience for everyone in the universe. The God of Thunder has some personal experience in this regard as well; had he successfully killed Thanos right away, both Iron Man (Robert Downey Jr.) and Black Widow (Scarlett Johansson) wouldn't have had to sacrifice themselves.
Gorr the God Butcher's interaction with Thor could bring back the guilt that initially plunged him into a deep depression after Avengers: Infinity War resulting in him Gorr the God Butcher's personal experience could ultimately re-open what are otherwise already healing wounds from the events of the Infinity Saga.
Given the limited information regarding Gorr the God Butcher, it's anybody's guess what his fate beyond Thor: Love and Thunder will be. Depending on how Thor handles the villain, however, he could be the God of Thunder's biggest test in his healing journey, after his experience with Thanos. This Thor and Gorr's encounter so much more compelling.