Lu Yang had an agreement with the Demon God Race: he would never lead troops to invade the Four God Star Territory. This was the foundation of cooperation between their two races.
Last time, the Turbid World Emperor and the Nightmare Lord had been deeply dissatisfied that Lu Yang had obtained a star territory and become its lord, placing himself on equal footing with them. But when Lu Yang came to the Four God Star Territory this time and contacted them, the Turbid World Emperor and the Nightmare Lord personally flew to the entrance of the star territory and welcomed him into Ruined Stone City in the Arctic Wasteland.
"Brother, that last war was truly satisfying. You killed three million auxiliary troops of the Celestial Race. You really took a huge weight off our shoulders," the Turbid World Emperor said enthusiastically.
The Nightmare Lord also patted Lu Yang on the shoulder and praised him. "You dealt a devastating blow to the Celestial Race and bought our Demon God Race a great deal of time."
If the Dark Celestial had defeated humanity, he could have turned around and led millions of God King Tier experts from two star territories in an all-out assault on the Demon God Race. At that point, whether the Turbid World Emperor and the Nightmare Lord could have led their people to survival would have been uncertain.
Now, the Celestial Race had to keep troops in the Primal Star Domain to prevent a surprise attack from Lu Yang. Those legions could not be moved, leaving only the forces in the Four God Star Territory to confront the Demon God Race. They could gain no advantage at all. This was the fundamental reason the Nightmare Lord and the Turbid World Emperor were grateful to Lu Yang.
Lu Yang