Bloody Hands

You cause the hands (or other appropriate body parts, such as claws or tentacles) of a creature within range to bleed profusely. The target must succeed on a Constitution saving throw or take 1 necrotic damage each round and suffer disadvantage on all melee and ranged attack rolls that require the use of its hands for the spell’s duration.

Casting any spell that has somatic or material components while under the influence of this spell requires a DC 10 Constitution saving throw. On a failed save, the spell is not cast but it is not lost; the casting can be attempted again in the next round.