Maybe Killing Stalking
http://www.mangago.me/read-manga/killing_stalking/mf/v00/c000/?av=1
It's pretty intense and has that stockholm syndrome feeling.
Also
http://www.mangago.me/read-manga/warehouse/
I haven't read it all the way, but the seme has kidnapped the uke.
This one isn't very similar but
http://www.mangago.me/read-manga/an_uncomfortable_truth/
In fact, it's not even yaoi but the story is intense and the mc seems to be a murderer.
http://www.mangago.me/read-manga/if_you_hate_me_that_much/
The seme rapes uke over and over but the uke still loves him don't worry it has good ending <3
Also this one, though it isn't on mangago but it is a manwha like Royal Servant.
http://www.webtoons.com/en/romance/winter-woods/list?title_no=344
I don't know why, but I was reminded of this when I read Royal Servant, though in all honesty it isn't similar at all, but it does have that heavy drama, at least at the end.
Omaigodd!!that's a lot of manga and very interesting...really!!! But I want a hetero version male and female...sorry if I confuse you
Oh oops, sorry I didn't see that hetero word. All I can say is, something like that is probably rare. Actually, Full Moon wo Sagashite is a fantasy with heavy drama at the end, but it is an anime. Trust me, you gonna need tissues for that. Also the Winter Woods one is hetero.
Ohh okay I will try to watch it...thank you
Hey,has anybody know what manga that has a same genre as Royal servant but hetero??? Or something like Stockholm syndrome??