Isnt it the same as the other manga. Hmmm..

Yep. Same as this one:
http://www.mangago.zone/read-manga/kage_no_jitsuryokusha_ni_naritakute/

Yeah, I was also extremely confused when I saw the title and then read the first chappie to make sure I was not going insane from captivity, but yeah its exactly the same. But if this one updates more then I'm chill. ╮(￣▽￣)╭

yea and the other one is already at ch 18 so it's ahead of this one