A newcomer looking for a specific faction

So I’m new to Warhammer 40K because of space marine 2 as I feel a lot of people are, and in the online mode you can pick which faction you want and I’ve done a bit of research on a few of them that have peaked my interest but I haven’t really found any that fit what I’m looking for, now correct me if I’m wrong but I play Dungeons and Dragons so I thought it would be cool to bring my character from there over into 40k which I believe is also has some roleplaying, now I’m looking for a faction that has royal background but strayed away from it in a rebellious way, now I don’t know if there is a faction like that so if not I’m open to doing more research on other factions and not making my DND character, I’ve been taking a liking to the Space Wolves and Dark Legion because I think their lore is cool and they also look pretty cool, any suggestions or general help would be greatly appreciated