Since we've initially identified the primary suspect as Shan Liangyi, all Liangyi inheritors must set aside their disputes and concentrate all efforts on killing King Zhuanlun first. Cooperation with Taoyuan Village Master Meng Zhang isn't out of the question, but I'm very aware that practically achieving this direction is challenging, and Water Navy Xuanwu probably knows this as well.
Because Meng Zhang has no need to join forces with us. It was only due to Xuanming's presence before that he couldn't complete the "Paradise"; now that Xuanming is dead, he only needs to finish the last bit of progress to become the brainchild of "Paradise," an ultimate existence even Impermanence cannot reach.