Magical Backfiring

Usually just called Backfiring or Backfire. This is something that can go wrong when you are trying to 'cast' a 'spell'. Backfire is an immediate negative effect. Importantly, it is always a temporary effect, but it is also always painful.

Common examples are bleeding from the eyes and/or ears, loss of vision and/or hearing, muscle spasms, seizures, and diarrhea.