Void Rend

A blade of dark energy streaks toward a creature within range as you brandish the weapon used in the spell's casting. Make a ranged spell attack against the target. On a hit, the target takes 1d12 force damage. If you score a critical hit against a creature that has fewer than 100 hit points, it must succeed on a Constitution saving throw or be slain instantly as the blade tears its life force from its body (a construct or an undead is immune).

This spell's damage increases by 1d12 when you reach 5th level (2d12), 11th level (3d12), and 17th level (4d12).