Why The Echelon Exists!

Meng Hao had risen to the top among the true Immortals, and was the Immortal Realm Paragon. After absorbing the Nirvana Fruits, he could leap into the legendary and ancient Immortal Emperor Realm, in which he could slaughter Ancient Realm cultivators with two extinguished Soul Lamps. He had long since shaken the entire Ninth Mountain and Sea.

When you added in his performance as Fang Mu in the Three Great Daoist Societies' trial by fire, he was clearly the most prominent figure in the Immortal Realm. As a result, each of the Three Great Daoist Societies was determined to have him.