Monsters level up when they kill people, it would be nice if a monster or boss could level up when killing a player.
I think that is a great idea. If a monster kills enough people he levels up, but they should put a maximun level up capacity, like a monster can only increase ten levels from its initial form, in the chase they reach theyr maximun level they give a lot of xp and better loot but it will be more difficult to kill.