James O'Brien

In the mirror universe, Captain James O'Brien is a male $𝜇$, the son of Miles "Smiley" O'Brien and $𝜇$.

Star Trek Online
James O'Brien was born to Miles "Smiley" O'Brien and Keiko Ishikawa. In this version of the mirror universe, The Terran Empire (now called the Terran Federation) was successfully restored as a galactic power following the Klingon-Cardassian Alliance's defeat at the hands of the Terran Rebellion.

Growing up, James was told stories by his father about visitors from the primary universe, whom he referred to as "goodie-goodie types". James did not hold a high opinion of his father, remarking on how ironic it was that Miles spent so much time fighting against the Klingon-Cardassian Alliance, only to lose everything to his own son. At some point, James killed his father.

By 2409, James had become Emperor of the Terran Federation, as well as captain of the ISS Molly. After traveling to the primary universe, James took over a Silithium mining facility in orbit of Bajor VII. He tried to use the silithium to redirect the Bajoran wormhole to the mirror universe so that thousands of Imperial ships could conquer the Federation. However, this plot failed when the Bajor VII mining facility was compromised due to the arrival of Starfleet officers.

Upon being retrieved by the Molly, the ship warped towards the Bajoran wormhole and engaged the Starfleet vessel in pursuit to divert it from O'Brien's efforts to redirect the wormhole to the mirror universe. Starfleet destroyed the Molly, killing O'Brien and preventing damage to the wormhole.