Yes, it's intentional (the spell lets you get through dungeons but you don't get any loot, so you're not gonna get stronger if you use it too much)
(Kinda inspired by Mask Le Smith in Killer 7)
Well I have all the stuff bought from the shop, so I dont really need money anyways :-)one funny combo seems to be poison and lightning.first poison enemies and then smash the lightning spell.bosses sure become easy too:poison then. and then jsut run away till they drop dead :-)