So for an added thing to do in Retale 2, there'll be one person that'll level the more you play him. Or in simpler terms:
He'll get harder the more you battle him. Sort of a NPC to test how strong you've managed to make yourself with the weapons you've bought and your click speed/Reaction times of blocking attacks.
In summary, these NPC's will:
=Get more difficult the more you battle them
=They won't level up however if you don't win against them, making sure they don't get more powerful even when you lose
=Attack back at you, if they hit you successfully, then they will gain +10 to their health. (Health is unlimited)
=Time limited battle, after a certain amount of time the NPC will win if you do not click fast enough. (In this case, like we said before, they will not level up and instead revert back to the power level they were when you challenged them. So you can keep trying at that level till you win.