Decay

In your line of sight you may curse one creature for 10 rounds. The creature takes 4d12 necrotic damage every turn after this spell is cast. 

This spell also removes 1 point of constitution from the affected creature every round. If the creature has 8 constitution at any point during this spell, then it’s movement speed is halved and the creature takes and extra 2d8 necrotic damage. 

If a creature reaches 0 constitution it dies instantly. Does not affect Undead, or a creature with immunity to necrotic damage.