Huh. Can't say I ever got that vibe from him. The story does initially set up that he's like that, but a pretty big twist early on is that he's just subconsciously using the FMC to project his own hatred of the world. He becomes pretty proactive throughout the rest of the story, both as a member of the Beast Knights (being both a main combatant and generally the one the younger group looks up to) and as the "traitor" (he deliberately develops and conceals a technique that is useless against the golems but completely dominates the other knights). And then of course the final reveal that halfway through the story he changed his goal from ending the world to saving the girl no matter what. If anything, Sami is the one who gets hit with a bit of the satellite syndrome and just ends up passively waiting for Yuuhi to do all of the stuff.