I hope you succeed, because the order would fall to me next.
~ Sulu to Mirror Spock
Hikaru Sulu is a mirror universe villain introduced in the Star Trek episode Mirror Mirror.
He was portrayed by George Takei.
Growing up, Sulu entered the Imperial Starfleet. Like his primary universe counterpart, Sulu served on the mirror universe version of the Enterprise under the command of Captain James T. Kirk. In addition to being the helmsman, he was also security chief and second officer of the Enterprise.
When the Captain or Mr. Spock were away from the bridge, Sulu liked to pursue Nyota Uhura, feeling that when the cats were away the mice could play.
In 2267, Captain Kirk, Montgomery Scott, Nyota Uhura, and Dr. McCoy were all transposed with their primary universe counterparts. When Kirk refused to destroy the Halkans, Sulu's suspicions were raised. His security board picked up extensive use of computer resources, as well as a communication from Starfleet to Spock, and deduced that Spock had orders to kill Kirk.
I do not want to command the Enterprise, but if it should befall me, I suggest you remember that my operatives would avenge my death. And some of them...are Vulcans.
~ Spock, warning Sulu about trying anything.
He started monitoring Spock's activities on the Enterprise. When Spock confronted him over it Sulu insinuiated that if Spock didn't take care of matters, Sulu would and that Spock should watch his back. Spock reminded Sulu that if anything happened to him that his operatives - especially the Vulcan ones - would come after whoever killed him. Sulu realized just how much danger he was in then.
However, Sulu soon saw his opportunity to take care of both Kirk and Spock in a way that would make it appear that the two had killed each other, and confronted them in sickbay. Marlena Moreau used the tantalus field to dispose of Sulu's posse, and Kirk knocked Sulu out.
A short time later everyone was returned to their respective home dimensions. Spock eventually took command of the Enterprise.
Spock tried to convince Kirk not to destroy the Halkans, but found him unwilling to bend. Spock killed Kirk a short time later, and used the tantalus field to dispose of Kirk's body. Sulu was quickly "neutralized" by Robert D'Amato.
In this permutation of the Mirror Universe Sulu was still alive in the 2290s. He tried to take over the Terran Empire but failed. He fled, with Pavel Chekov in hot pursuit.