Death punch

Death punch is what it sounds like; a punch that inflicts death. When casting this spell, opponents do not get an attack of opportunity against you for being in an adjacent square, unlike with most spells. Death punch is a punch delivered by the castor, after which the target must succeed in a fortitude save (DC 17) or die instantly. Creatures 2 or more levels below you are not entitled to this saving throw. If the target succeeds with the saving throw, it still takes 2d8 damage Times your castor level (to a maximum of infinite d6; the more OP you are, the more OP this punch is). If the castor so wishes, for cinematic purposes, their first is covered in flame (castor chooses the color), and/or creates a loud bang when it hits. Just for fun.