Cardinal Hildred's Grand Scheme!

Prior to this incident!

"Let me explain!"

Zero said to Saintess and Adeline as he explained all the events that happened during the ceremony.

"..."

Cardinal Hildred was listening to all the conversations between Saintess and Zero.

Adeline's mind control was not healed even with Saintess' healing. The only thing that made them believe that Adeline recovered was because Cardinal Hildred made it that way.

There was one function of Nexus Scepter that Zero was unaware of. The reason for that was because, in the novel, not much is said about Nexus Scepter as it gets destroyed by Hiro after finding that it is disastrous for humanity. There was only information about the artifact being able to control the minds of people in large numbers.

Anyway, while Zero was aware of some of its functionality, he had not personally used the artifact so he didn't know everything about it.