Mirror Wesley is the Emperor of the Terran Empire, who possesses incredible "personal power", including the ability to freeze entire fleets in a "time bubble". He plans to merge with "the Other", the mirror counterpart of V'ger, to become a god and destroy all who oppose him in every universe, starting with the prime universe.
Yeah dude, that Terran Gambit arc gets a little bonkers.
spoiler
A Terran task force attacks Jupiter Station for what they keep calling "The Emperor's Prize" which turns out to be Ilia from TMP in stasis. The strike team is composed of mirror Marshall Janeway (voice by KM), mirror Captain "Killy" Tilly (whom I found to be obnoxious), mirror Terran Admiral Leeta (voiced by CM) and your character's mirror counterpart the Inquisitor. The point is to use prime-Ilia to contact the mirror version of V'Ger, C'qer...pronounced seeker from the CONQUEROR satellite. Emperor Wesley plans to merge with it to obtain godlike powers and annihilate the prime universe and digitize entire planets. After they merge and he's wiped out half the prime solar system, He's only defeated when mirror Bev Crusher moms her way into him calming down as you simultaneously battle mirror Terran admiral Leeta who is possessed by a Pah-Wraith.