Saying you can use magic in this game is pretty disingenuous. You cannot be a spellcaster, mage, wizard, druid or anything like that.

There is basic alchemy which looks likely to be expanded.

Outside of the special powers from the boss, no, you cannot use magic. Out of the five powers we have at this point: two are defensive (one of which isn't necessary yet), one is stamina related, one is resource grinding, and one is environmental. There are a couple of weapons with magic properties which provide DOT and/or slow effects.