For the regular universe counterpart, see Styles.

In the mirror universe, Styles was a Terran captain in the Imperial Starfleet. He was the commander of the ISS Excelsior in the late 23rd century. He was found out to be working against Emperor Spock by Tuvok, who killed Styles and succeeded him as captain of the Excelsior. (VOY novel: The Mirror-Scaled Serpent)