Avasculate

A ray of black necromantic energy lashes out from your fingertips at a target within range, causing the target’s blood to boil and be violently purged from their body. Make a ranged spell attack against the target. On a hit, if the target has less than 200 hit points, they are reduced to half of their current total. If the target has more than 200 hit points, they instead take 10d10 + 30 Necrotic damage.

On a hit, the target must also succeed on a constitution saving throw or fall prone and become incapacitated, unable to get up until the end of the target’s next turn as it writhes in agony. 

This spell has no effect on constructs or undead.