With Roly Poly cradled in his arms, Zhao Yao was able to remain invisible as he walked down the passageway.
Now that Champion had recognized him, he had to conceal himself extra carefully. This required not only invisibility but Elizabeth's illusory powers as well. They ensured that no one would be able to see, hear, or even smell him.
This should be at least 99% effective. Unfortunately, Butcher belonged to the 1% that could still sense his presence.
After all, the illusions were carried and spread by sound waves. Having fought Zhao Yao before, Butcher knew how this worked. In fact, he had previously strained the muscles in his ears to block out the waves to protect himself from their reverberations.
He had experienced first-hand what they felt like and the familiar sensations warned him that danger was coming, even though Zhao Yao was still hundreds of meters away.
"You must all retreat immediately! Hurry! If not, it'll be too late."