Death Siphon

When this spell is cast, you deal 4d8 necrotic damage to all hostile creatures within a 30 radius sphere centered on yourself. You heal all the damage you deal. If this effect reduces a target to 0 HP, you heal double the damage dealt. If this spell affects a target already affected by Sanguine Touch, the target is paralyzed.

When a creature is affected with this spell, they must make a Constitution saving throw. On a successful save, the caster suffers 2d8 necrotic damage.