I was waiting to post mine to allow for other input, but here goes:
Akka is hanged for being a traitor, is blamed for the failure of the GO. While he’s twitching around on the rope in the throes of death, he finally “gets” the translocation cant and transports away all the way back to the GR ( he hasn’t figure out how to direct the ship, just sail it at this point ). It’s empty, no one’s there. He looks into the IF and sees himself being tormented by Kellhus endlessly. This puts some gas into his awareness and figures he has to find Mimara ASAP to avoid his destiny. He finds a head on the belt of a salt statue of Kellhaus and takes it with him.
Meanwhile, the boy is a fast learner and on the move – he’s quickly absorbing history, culture, tactics and infiltrates the Sylvendi. He quickly moves up in rank and becomes the hand to Moe Jr. Together they meet up with Kau/Serwa ( who now looks like an undead lich, but much more powerful than she was, no longer walks but floats ) to align with Zeum and the remainder of the 3 Seas to march on Golgotterath. But now they can take the short cut up through Ishterebinth, grabbing some remaining Cûnuroi along the way. Instead of 300,000, they are a band of warriors numbered around 5,000, all on horseback making the trek logistically feasible and faster, all armed with chorea.
With the help of the head, Akka finds Mimara and his son residing in the Library of Sauglish. Mimara has been using The Eye to help her research on how to destroy TNG – she has discovered that “saving” the souls of The Consult/TNG is the path for success. By bringing the damned back into the bosom of The God, the metaphysical error of the Outside of the Outside can be resolved ( turns out all of this mayhem was due to a mathematical rounding error, The God rounded to a trillionth in lieu of googolplexian ). Akka teleports the 3 of them to the GR, but falls short and they show up at Dagliash and connect with some “survivors” who at first attack them, but The Eye shows them who they were before they mutated from radiation and warn Akka out of the area to avoid radiation poisoning ( “do not become as us” ). A few mutated sorcerers and warriors join them as they march to the horns.
Altogether ( Akka, Mimara, Kau, Serwa, Moe Jr, the boy, et al ) they meet up outside The Occlusion. The boy collaborates with the head and together are able to solve the math problem – which is whoever/whatever sent the Inchoroi on their way through the cosmos was supposed to “save” 144,000 lives on each world to redeem themselves, not reduce it to that … all of this, a big misunderstanding of rounding issues with Infinity. So what was supposed to be an epic showdown becomes a rudimentary math class with TNG. The sorcerers with the help of nuclear mutated sorcery rebuild the Ark ( the radiated sorcerers go with them to power the engines ) and send The Consult on their way to repair the damage they’ve done to the thousands of worlds they terrorized. TNG reunites with his father through the IF, which closes that portal; Mimara accompanies him/it with the hope of saving those in hell with The Eye. Earwa is released from the womb plague, Akka raises his son, Serwa seizes rulership of the 3 Seas with Moe Jr and Kau as her generals. After 20 years, with humanity normalizing, Eanna invades Earwa igniting a mass world war.