You start chanting.
You are casting 'magic missile'.
You are done with the chant.
You boom in sinister voice 'gtzt zur fehh'
You falter and fumble the spell. Amazingly it fires upon yourself.
You feel like your spell gained additional power.
A magic missile hits you.
You watch with astonishment as your magic missile hits yourself.
You scream in pain under extreme magical pressure, you think you are DYING!