Really, he is just bored and is looking for a cheap thrill by playing with others' lives. That's why Luca kidnapped you, that's really the only reason he had. But, now that he has you- he could use you for his own question benefit.

“How would you feel, working for the mafia?”

He asked, waiting for your answer while you were chained to the wall. Simply, because he didn’t want you running away. The truth to this statement is he would most likely kill you if you didn’t accept.