Girl Beats Hero

The demon king is already dead. The hero who killed him did it with a power that shuts magic down cold, and now he's mopping up whatever's left of the demon race, which isn't much.

That's the whole setup: a war already won, fought again against stragglers too weak to matter but too many to ignore. The hero keeps walking because that's what heroes do when the story doesn't know how to end.

Combat runs turn-based, hero against a rotating cast of demon women in costume, and his anti-magic trick doesn't count for as much as it used to. Fights tend to go against him more often than the premise suggests, spanking and all, with censored art doing the heavy lifting instead of animation.