Is because of that pushovers are hated in manga by the readers... '-'
I would had killed the king and let him be replaced by someone else and it would end... '-'
If the next King do it again killing that one too... until they given up... '-'
I'm not sure he's adjusted enough to understand the appropriate way of treating someone, although I don't think he'd mind if she treated him the same way. It's rather unusual, though, since the roles are almost always reversed in who abuses who, because that's more "accepted".
Creative use of portals for partial transformation attacks.
I like that nobody believes the hero was killed. Someone even pointed out the stupidity of trying to make such a statement when chapter 1 opens with a segment from the future where he's clearly alive and well with his wife and 2 daughters.