Bleh... feels like some kind of s---ty edgelord fanfiction. I guess in manga like Healer(Kaifuku Jutsushi no Yarinaoshi) we can at least see himself build up a little from being a humiliated slave to how he behaves currently with a more sadistic mindset toward his enemies, but here, its just like instant; he goes from being shown as a 'noble' hero, then the very next page, turns evil and hate-filled. Then his expressions toward the goddess are more of a deranged, evil man than a person who wants revenge. It's very off-putting.