Coup de grace

You’ve developed a skill for delivering a death blow, either as a mercy killing or a merciless execution.

In place of an attack on your turn, you may use a melee or ranged weapon to deliver a Coup de grace attack to a prone beast, humanoid, or lesser Undead (CR of 3 or less) within 5 feet of you. To do this, the creature' s challege rating can be no greater then half your level rounded down. The attack does critical damage on a hit.

While delivering a Coup de grace, you provoke attacks of opportunity from creatures within a range of 5 feet of you. When you deliver a Coup de grace, your speed is reduced to 0  until the start of your next turn.