Daybreaker's Deadline

A blood red mockery of the moon forms into existence above you, rotting itself into the minds and bodies of your choosing. You emit a 30-ft Emanation for the duration. This spell can affect a number of creatures in the Emanation equal to your spellcasting modifier. The affected creatures have their speed halved, and must make a wisdom saving throw. On a fail, choose two from the effects listed below to affect each creature that failed.

• They have disadvantage on all saving throws as both their body and mind atrophy and deteriorate.
•  They gain a -3 penalty to their AC while the Deadline is still active. In addition, they cannot benefit from the Invisible condition.
• Each creature affected by this spell take 3d10 necrotic damage at the end of their turns.

Creatures that failed the wisdom saving throw can repeat it on the end of their next turns, ending the effects on them on a successful save. They can also end the effects of the spell on themselves by exiting the Emanation. If a creature leaves the Emanation, you may choose another creature in the Emanation to be affected. Each time an affected creature fails the saving throw on subsequent turns, they take 3d10 necrotic damage. 

Using a Higher-Level Spell Slot. All damage done by this spell increases by 1d10, and it can affect one additional creature for each spell slot level above 6th.