Because Abner had chosen to advance to Wisdom Angel rather than Profane Presbyter, the Ancient God he had named Demon Emperor—stitched together from the Unique of Abyss, one Dark Angel Beyonder Characteristic, one Filthy Monarch Beyonder Characteristic, and one Demoness of Apocalypse Beyonder Characteristic—needed Derrick as its "cornerstone" to come into being.
After Derrick had "died," he became Sealed Artifact 1-025. Later, during the scheme to rescue Tolzna, he was Sacrificed back into the body of the Chained God.
Of course, this had been Derrick's own calculation. He was originally the Chained God's God's Left Hand, a part of Him. After being used by the Church of Storms for centuries and completing the ritual of the Ancient Bane, he returned to the Chained God's body. As long as Abner used the Secret Art of Resurrection on him, he would immediately advance to Sequence 2, just like Alvin and Evans.
However, the Chained God's body was currently in Suah's hands, and that Abomination had most likely already been corrupted by the Mother Goddess of Depravity. While there was a chance of victory if they went to seize the body now, there were too many variables. Abner decided to play it safe and wait until he possessed god-level strength.
Moreover, this matter involved the Silver Moon Plan, so Lilith's consent was required.
Hearing Abner's answer, Sia Palenque Eggers nodded slightly. "I guessed you would have considered that reviving Derrick would inevitably mean facing some of the contingencies he left behind... It's good for you to become the Emperor of Knowledge and Fate first. That will also make Tolzna give up completely, so she doesn't make the wrong choice."
"That was my thinking too." Abner nodded with a smile. He chatted with the goddess's avatar for a while longer before bidding her farewell