It was quite obvious that Blood Maiden was extremely stubborn and it would be hard to convince her. She showed no reaction to Number One's suggestion which forced him to change his tactic.
"I'm sure you think that my proposal is laughable because there is no way a young man like me could possibly get what you want. You already got everything a person of your status could get and you are comfortable just retiring in this place," Number One pointed out. "But what about other things that you couldn't get? What about Soul Artifacts that you never dreamed of having the opportunity to study?"