Krell (22nd century)

From Memory Alpha, the free Star Trek reference.

Krell was a Klingon Fleet Admiral who attempted to destroy Qu'Vat colony after it became infected with a Klingon augment virus. He was in league with Agent Harris of Section 31 in an effort to eradicate the augments, which they believed would be benefical to both governments. Despite Phlox's assurances that he had developed a treatment, Krell still was going to destroy the colony. Krell became more receptive after Phlox beamed a sample of the virus onto the bridge of Krell's ship, infecting him and his crew. Phlox refused to give him the cure unless Krell powered down his weapons, which he did. Krell convinced the Klingon Council to end its plans to sterilize the colony, promising to distribute the cure throughout the Empire. (ENT: "Divergence")

Krell was played by Wayne Grace. He was the first Klingon Admiral ever seen onscreen.