Cataylst

Focusing your ill will upon a creature, you worsen the poison already within them, wracking them with horrible pain.
To clarify, this spell can only target a creature that is poisoned.
The target must succeed on a Constitution saving throw or take 3d12 poison damage and the whatever amount of time is left on the poison they are currently suffering from is now *doubled*. Once doubled, the poison cannot have its time increased by this spell until the time left on it either runs out, the creature saves from the poison and is no longer effected by it, or a new poison is introduced. Casting this spell on the same creature again only results in the creature taking more damage, as the poison can no longer be increased (until other criteria is met). On a successful saving throw, the target takes half damage and suffers no other effects.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d12 for each slot level above 2nd.