[X] Plan Let's Do The Time Warp Again
-[X][Ally]Leman Russ
-[X][Ally]Ferrus Manus
-[X][Ally]Fulgrim*****
-[X][Enemy]Roboute Guilliman******
-[X][Enemy]Lorgar******
-[X][Enemy]Perturabo*
-[X][Virtue]Curiosity
-[X][Vice[Flippancy
-[X][Special Trait]Achron
Achron is a strategy game where you and your opponent go back and forth in time. I assume it comes from the 'a-' prefix, indicating a state of 'not' or 'opposite', like moral vs amoral, then chron presumably being some weird morph of chronology. That just inherently seems more interesting to me than yet another genetic engineering person. The sorts of tactics and strategies and ruses that could come from omnidirectional travel through time are nuts.
As for everything else
Leman Russ was selected for a reason which I will ask you to guess. You get three, the first two don't count. Ferrus Manus and Fulgrim is something similar to Plan Emotions's pairing of Horus and Sanguinius to create potential internal turmoil. Flippancy as a Vice isn't just for "haha let's mock 40K" purposes, it provides the chance to have our Primarch struggle with having an attitude totally at odds with the rest of the universe, not taking things as seriously as he should and getting mouthy when he shouldn't. Curiosity seems to fit best with being a time traveler of sorts. Even if that's not what Achron is, I enjoy curiosity as a character trait. Our enemies are selected to be... honestly, I mostly chose them out of personal dislike, but they're also more serious, prideful types with set ways, which goes against the vice and virtue.