The tsunami was imminent, with no escape possible.
Indeed, there were no roads to heaven and no doors into the earth; was Xu Xiaoshou truly without retreat?
No!
His "Independence" and "Vanishing Technique" could erase his existence from the root. Even if the Di Ying Holy Plant was still perceptive, its first reaction would certainly be to devour the coffin and Yue Gongli first.
This was the best strategy of sacrificing others to save oneself.
His backup plan with the Fourth Sword was initially aimed at Yue Gongli, but it hadn't returned to his hands yet. After the sudden emergence of the Di Ying Holy Plant, he immediately set an anchor point on the spot.
His second true body was far outside the Divine Relics, and his connection was severed at that moment.