In the mirror universe, Legate Renar was the supreme commander of the Cardassian Union in the late 23rd century.

In 2293, Emperor Spock of the Terran Empire postulated that following the failure of the Khitomer Conference, that Renar and Regent Gorkon of the Klingon Empire, would meet to discuss a grand alliance between the Klingon and Cardassian, which would allow them to defeat the Terran Empire.

Spock was eventually proven correct in 2295, when the Terran Republic was completely defeated, and Renar and Gorkon were able to take Consul Spock and his wife, Marlena Moreau, prisoner after storming the Kyoto Imperial Palace. After Spock declared that the end of the Terran Republic, would mean the end of Renar's empire, Renar had them both executed. (TOS - Mirror Universe novel: The Sorrows of Empire)

It is unknown whether Renar had a counterpart in the primary universe.