[@6slyboy6] Here's why, for them it feels like they're being controlled, they don't like the fact that they can't look at Humanity's history, they don't like the fact that they are forced to live on planets with Xenos, and because of this their faith in the Empire and the Emperor has been lost, they also don't like the fact that one man can make or break the Empire even though it's been proven to them that the Emperor is capable, they don't like being under the Emperor's thumb.

Another thing, is even though humanity has taken the Triangulum, the people who join the Black sun feel like it's not theirs, it feels like it belongs to one man, which puts them off.

[@Wernher] They could have been crushed by Admiral Konev and the Cravens in the past, which would put Konev and Martin Kell in an interesting position don't you think? It would give the Black Sun more reason to rebel, and even if the Black Sun suddenly grew to like Xenos then they'd just turn around to support Xenos, so I've put some of that into context of development like, it'd be more in character, since I see that event as more current and more fitting to be put in IC, but I would like your opinions on that regard.