Mishima

Mishima was a mortal who was given a tiny fraction of omnipotent powers by the rogue X in 2377. This gave him the status of omni'X, and he, like all other omni'X the next year, lost all given power after trying to create the X Continuum. (: "Vengeance", "Avalon Battlefield, Part II")

The First X Continuum
Mishima was the only omni'X with an open communication with the rogue X, during thier existence from 2377 to 2378. This was attributed to his special power, as every omni'X retained a unique powerful ability. In a way, his open communication had made him the highest ranking omni'X out of all; so much that, while in the X-Time bubble, he stood closest to where the rogue X resided and where the X Continuum was to be created.

While there, he fought Daniel, who wished to speak to the rogue X. Mishima saw the fighting itself as a way to increase his power so that he could join the X Continuum a lot faster. (PNX: "Avalon Battlefield, Part II")

Post Continuum
After the failure of the X Continuum, Mishima roamed the galaxy, trying to increase his reduced power. He hoped that with it, he, and others, would be able to create another X Continuum.

Unfortunately, a timeless war, brought on by the time-travelling Klokian began to escalate in 2380.