I would maybe make it a bit more exciting and also condense a lot of it. It's also a bit confusing because he goes from warrior to thug to "oh wait so he's a king?", which should have been clear in the beginning.
Something like:
"Robbed of his rightful claim to the throne, Erilaz and his companions are forced into exile. They must survive on a distant planet under the guise of common criminals, and beneath the fist of ruthless gang leader, Bob Smith."
Just a rewrite of a few lines but it pulls you in better and reads less like an autobiography.
From an artistic standpoint the cover doesn't depict the synopsis well. Maybe have something like a cosmos or alien moon or something in the background so we know there's a scifi element to it.
