Come to think of it, since the Lord of the Universe hadn't possessed them while Ling Tian and the others were still in the God Realm, it had to be because their cultivation realms weren't high enough. Otherwise, why would he bother letting them "out of the universe"? He could have simply possessed them directly.
After a brief pause, Chi Xue said, "That's right. It seems the Lord of the Universe released us so we could improve our cultivation as quickly as possible. After all, the environment beyond the starfield is far better than the God Realm's. In particular, we can find every Saint-grade Heavenly Treasure in the starfield, and using them will further accelerate our cultivation. The Lord of the Universe may need us to reach a certain level so he can improve his physical condition as much as possible. Fellow Daoist Ling Tian, what level do you think he needs us to reach—or, more accurately, what level do you need to reach—for him to possess you?"
Though he phrased it as a question, anyone could tell from Chi Xue's tone that he already had a theory—and was quite certain of it.
Ling Tian didn't hide his thoughts on the matter. "I suspect the Lord of the Universe wants me to reach the Saint level, or at the very least come infinitely close to it. Only then could possessing me improve his condition. He mentioned reaching the Saint level more than once while we were cultivating, and specifically talked about using Primordial Chaos Qi, fused from Saint-grade Heavenly Treasures, to break through to the Saint level. That tells us he needs us to reach the Saint level—or at least needs me to come infinitely close to it. He won't act against me before I reach the Saint level or