I had to skim back a little but i still might wrong but i don’t think he knew that, that was his brother. arielle_
yes, he didnt know he was brother's with the dude that used him. but to think he lied to him to try and get closer? Their first encounter was him trying to kill demons with a knife! i think he was pretty honest with his intentions since the beginning.
Why are you feeling betrayed when he tried to kill you multiple times when you first meet!