Beam of Die Immediately

This Spell can only be used once per campaign. Target 1 non-crucial creature to the plot of the campaign. Roll a d20, on a natural 20, the creature dies immediately. On a natural 1, the caster of the spell dies immediately. Anything else rolled on the dice will result in nothing happening and the spell failing and you may not attempt to cast this spell again. It is removed from your learned spells list and replaced with another spell you may learn.