They probably didn't intend to return it. He didn't even know these two men; once they took the spirit crystals, would they actually give them back? Of course not. Besides, he didn't even have any spirit crystals on him.
"I don't have any spirit crystals."
"You don't? Listen, kid, I'm trying to ask nicely, so you'd better be sensible. Otherwise, don't blame me for tearing your mouth apart."
Chapter 720