Knight wants

Knight was a mighty warrior, the mere sight of him sent armies fleeing and he was known far and wide for being a merciless killer.

...So why the fuck was some short white-haired chick annihilating him so easily? The thought made him burn with rage. Lysithea was a magical nuke encased in a tiny body. She was renowned for her magical prowess, but even the knowledge that at least he'd lost to a worthy opponent didn't slake Knight's thirst for vengeance. His plans had... changed, however.

Normally, he would simply kill whoever had offended him, and so this was his original plan- fight and kill her. But one day, in another heated battle, the tip of his scythe had cut through her clothing, exposing milky white skin and a lithe body, albeit somewhat underdeveloped for her age. He didn't see anything explicit, but just the thought of it had changed his simple plan for violent and bloody into something more...sexual.