Anyone know of games similar to this style? Own a domain, attack/capture/get people, level them up build relationships. Force them/build relationship to do 'stuff'. 

I'm quite enjoying this game however it is lacking a lot of content, so just wondering if anyone had a similar game to this one?

other than maybe Strive for Power? or the games like StationMaster or Fort of Chains, not really, and definitely not this... interactive. S4P is mostly juicy writing with a gallery for game events, and FoC has some images for events and choices, but nothing, again, interactive outside raunchy writing and your imagination. there are a few other sort of "farm" games on this platform, the first one to spring to mind that is similar to this is SlaveBar (SlaveBar M ~ Episode 1 [v1.4] by nymphokyun) 

Well...if you're not looking for anything kinky or lewd - obviously the OG Dungeon Keeper games. Though a bit outdated, these ARE video game classics (Original DK invented the "hand-cursor" & slapping minions^^), and still good fun to play.