Bone Break

Skuldur's blood magic guides your hands as you temporarily crack apart the bones of one creature you can see within range. The target makes a constitution saving throw. On a failed save, the target takes 4d6 bludgeoning damage, and until the end of its next turn, its speed is halved and it has disadvantage on weapon attacks. On a succesful save, it takes half as much damage and suffers no other effects. 

If the target is undead, it has disadvantage on the saving throw and is knocked prone on a failed save. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the bludgeoning damage increases by 1d6 and every enemy attack roll adds 1d4 necrotic damage.