To shatter Xiao Yan's will, a single avatar was not enough. Amon had deployed his Main Body!
He had divided his Main Body into two. One was the Main Body with the highest cultivation, the Main Body defined in terms of rules by the talent bestowed upon him by the Battle Through the Heavens Universe based on his own traits: "Amon's total mass shall not exceed one hundred times that of the Main Body, and an avatar's mass shall not exceed one-tenth that of the Main Body." The other was his spiritual Main Body, the Main Body of his self-perception!
The two did not necessarily completely overlap; they could be separated!
This would make the status of the Main Body ambiguous, blurring Amon's anchor upon himself and possibly driving him even madder.
However, Amon did not mind taking a risk... He sent his spiritual Main Body, carrying that trace of Celestial Worthy's will, to Xiao Yan's side!
Xiao Meng herself was a personality Amon had deliberately adjusted. After devouring Zhu Kun, the Taixu Ancient Dragon Emperor, Amon replaced the Spirit Worm carrying that false personality, allowing the will of his Main Body to sleep beneath it. It would awaken only when certain conditions were met.
That condition was for Amon's will to contend with the wills of the other two Masters and enter a brief deadlock... If that condition was not met, the will of his Main Body would sleep forever, and Xiao Meng would forever remain Xiao Meng.
While his Main Body's spirit slumbered, Amon was also slowly merging with that trace of Celestial Worthy's spirit in order to strengthen his own will. This seemed dangerous, but the risk was not actually that great.
Though that trace of Celestial Worthy's will was lofty in essence, it was like duckweed