Spoiler warning: Plot and/or ending details follow.
That same year, when T'Kuvma contacted the Council and attempted to rally the Great Houses to his cause, Kol refused to listen, and demanded T'Kuvma show some respect (since T'Kuvma was not a Council member). Kol vowed that he would one day put T'Kuvma in his place, then ended the communication. (DSC episode: "Battle at the Binary Stars")
T'Kuvma died before Kol could carry out that threat. However, Kol later transported aboard T'Kuvma's ship and convinced the starving followers of Voq (T'Kuvma's protege) to abandon Voq, by bribing them with food. Kol then ordered L'Rell to kill Voq immediately, however L'Rell was able to convince Kol to exile Voq to the wreck of the USS Shenzhou. (DSC episode: "The Butcher's Knife Cares Not for the Lamb's Cry")
Kol later consolidated his power over the High Council and expelled all Great Houses that were not allied with him. Kol spread the rumor that the Houses of D'Ghor and Mo'Kai were seeking an alliance with the Federation, in an attempt to lure a high level Federation operative into a trap. Kol had sought to capture Sarek, but Admiral Katrina Cornwell was sent in Sarek's place. Kol had Cornwell's security escort killed and the Admiral was imprisoned. (DSC episode: "Lethe")
Kol transferred his flag to the Sarcophagus, the ancient Klingon vessel which Kol had appropriated from Voq and his followers. After Michael Burnham snuck aboard the Sarcophagus and planted sensors on board the vessel (which would enable Starfleet to penetrate the ship's cloaking device), Kol discovered Burnham's ruse and accepted her challenge to ritual combat. After Burnham was beamed away mid-battle, the Sarcophagus was destroyed by the USS Discovery, killing everyone on board, including Kol. (DSC episode: "Into the Forest I Go")
- DSC - The Light of Kahless comic: "Issue 4"
- DSC episode: "Battle at the Binary Stars" (first appearance)
- DSC episode: "The Butcher's Knife Cares Not for the Lamb's Cry"
- DSC episode: "Lethe"
- DSC episode: "Si Vis Pacem, Para Bellum"
- DSC episode: "Into the Forest I Go"