In the end, the war between the Nine Regions and the Immortal World was a war for time.
If the Immortal World came to the Nine Regions several hundred years later, Wang Lu could integrate all the forces in Nine Regions and nip the invasion of the Immortal World in the bud. Of course, if the Immortal World couldn't open the passage between the two realms within a few hundred years, it would've kept on declining.
In this war for time, the Immortal World took advantage of its great strength to laugh at the end. Finally, the two-world passage was opened ahead of time. Wang Lu's many plans for the Nine Regions came to an abrupt end and had to respond to the war hastily. At the beginning of the war, although the Immortals were cautious, the Nine Regions were still in a strained circumstance. Even he himself was trapped in the two-world passageway by Yanluo's scheme. It could be said that he was defeated miserably.