Manga

I'm wondering if this is some sort of corruption of the hero, or if there's some necromancy thing going on. They said it was someone who was supposed to be a hero, but don't mention an explicit timeframe. Was it like a year ago? Or 2 centuries beforehand?

Also, the knight has a higher voice? We just know that's going to be yet another love interest, huh? My bet is on tsundere knight who doesn't know how to show affection.