Decaying Touch

casting this spell causes necrotic energy to swirls around your hands you can make a melee spell attack, on a hit the creature takes 8d8 Necrotic Damage, that spot starts to decay like dead flesh within a matter of seconds. this spells is active untill it hits its target or is dismissed. if a creature is reduced to zero by this spell they crumble to dust, if they aren't once healed by magic or over time the creature is left with a black discolored hand print of the caster. 

At higher level the spell deals additional 1d8 for damage.