Curdle Blood

The user utters an incantation and draws their own blood (user takes 2D6 Sacrifice damage). They then launch a blood ball in a 20ft spherical radius, all creatures within the sphere must make a Constitution Saving throw against the casters Spell DC. On a failed save the target takes 7D8 + 32 Necrotic damage, and half as much on a successful save. 

Creatures who fail the save also become "diseased".

Every round the creatures in the sphere take 4D6 Necrotic Damage unless they are outside of the spheres radius.

Objects and creatures within the area of effect that do not contain blood are not effected by this spell.