I think, it all comes down to, "Onyx Prime...have you come to draw us together or pull us apart?" -- "Sometimes, Mistress...a leader must do one to accomplish the other."
So, all the players are eventually brought into one place, literally drawn together.
The explosion happens. I don't know how or why.
Doubt is cast among them all. A unified Cybertron is in disorder.
Liege Maximo is left smiling.

What I don't know...
Is Onyx Prime a part of Maximo's plan? I don't think so because he seems genuinely pissed off about Alpha Trion.
What happened to Soundwave? I think somehow Maximo influenced him and broke down the control Soundwave showed at the start of the book.
Is there an unreliable narrator here? Was some part of what we saw and read not truthful?