Antari’s Absolute Severance

Uttering ancient words, you slice your fingers through the air, describing a straight line across one creature or object you can see within range. An object makes no saving throw, and is severed along this line with perfect precision. A creature targeted by this spell makes a Dexterity saving throw. On a failed save, it loses a limb of the casters choosing, and takes 20d6+20 slashing damage. This damage ignores resistance or immunity to slashing damage. Losing an arm prevents somatic components of spellcasting, and losing a leg imposes disadvantage on attack rolls and dexterity saving throws. If it fails by 5 or more, it is bisected in addition to this, reducing its movement speed to 10ft and automatically failing strength and dexterity saving throws, and it cannot rise from a prone position. On a successful save, a creature takes half damage and is not injured.