A Klingon commander of the House of Kor who seized T'Kuvma's ship and cloaking technology to dominate the war against the Federation.
Kol was a Klingon commander of the House of Kor and a rival of T'Kuvma's movement. After T'Kuvma's death he took control of the sarcophagus ship and stranded Voq, then won the loyalty of many Great Houses by sharing the cloaking technology that let Klingon ships attack Federation targets unseen.
Under Kol the Klingons gained the upper hand in the war, and L'Rell, outwardly loyal to him, worked against him in secret. Discovery's crew finally developed a way to penetrate the cloak, and Michael Burnham and Ash Tyler boarded his flagship to plant sensors, with Burnham fighting Kol before being beamed away.
Discovery then destroyed the sarcophagus ship, killing Kol. Kenneth Mitchell, who played Kol, also portrayed his father Kol-Sha in the second season.