The Simple Method

The soul was something everyone gained some control over after reaching the Soul Transformation Realm. The higher one's cultivation after that, the better that control was. After the Transition Realm, it was even possible to bring one's soul out, although no one was crazy enough to do such a thing. You never know what side-effects could be there in such situations. Even worse, you might be targeted during such a moment.

However, before the Divinity Realm Scaled Seal destroyed their bodies, Rean contacted Gram, Duleti and Farlo. He gave them one choice. Let go of their bodies and allow him to take their souls. He possibly could save them.