Slave of Black Knight

Slave of Black Knight is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.com fastest updating comic site. The Summary is

I worked like a slave in the chivalric order, where all the outcomes were exploited my senior, but I was scouted by a pretty little girl who called herself a guildmaster.
Initially I accept it half-jokingly but after I was shown a great sum of advance payment, I decide to leave the chivalric order. When I went to the guild, even the title of S-rank was prepared.
—This is a success story of a man who has never had a good thing since he was born