Blood Restraint

You select a creature you can see within range. Necrotic energy enters the blood stream and begins to thicken. The target must make a save vs Spell DC. A failed save, the creature takes 4d8 Necrotic Damage and is paralyzed. A paralyzed creature can make a save at the end of its next turn see if the paralyze effect is removed. The creature is paralyzed until it makes a save or spell to remove the effect is cast. 

On a successful save, the creature takes half the Necrotic Damage, but is not paralyzed.