Thanks for the reply! I'll look into the controller, see if there is a workaround in the unity input system for that specific controller, there must be!
The abilities are a bit mega man-esque. You unlock a new ability after each boss you beat, and each one is used by the same button. Then there's an additional button to "scroll" through the abilities. It's a bit oldschool, but we thought it worked well with the bosses I designed and on top of that, it's scalable fairly well without ending up with many, many, buttons :D