Paghal

Paghal was a Klingon who was a Fleet Commander in the Defense Forces in the 2370s. He was assigned to the same ship as Kaybok when they were younger. It was the first ship they served on.

Paghal later led Klingon forces during the invasion of the Cardassian Union in 2372. After Commander Kaybok failed to search and destroy the SS Xhosa and several of his crew were killed, Paghal transported to the IKS M'Char with General Martok.

Paghal killed Kaybok with his former crewmate's own d'k tahg, showing no sign of regret at killing his former fellow officer. (DS9 novelization: "The Way of the Warrior")