It was like insurance for Bai Chen, and that was why he finally said that he would accept the Power Crystal that Bai Lang would give him. After all, he wasn't the one who forced Bai Lang to give him the crystal. It was Bai Lang who voluntarily offered his Power Crystal, and Bai Lang also said that he would be fine without the crystal.
Perhaps Bai Lang was right that he didn't need the Power Crystal. Bai Lang didn't have a physical body anymore, and it could be said that he wouldn't be able to use the crystal anymore without borrowing someone's body. That was why Bai Chen had agreed to accept the crystal, thinking that perhaps it would be of some use if it were transferred to his body.