Gazef Stronoff knows there’s no way he can win, but he’ll fight Ains Ooal Gown anyway. As Head Warrior he is the sword of his kingdom; if he doesn’t face their greatest foe, who will? All other considerations are secondary.
While an argument could be made there was far more Brain, Climb, and other warriors of the kingdom could have learned from Gazef, staying alive to teach them would have meant some kind of surrender against Gown, which his code simply would not allow.
Gown defeats him easily by stopping time and casting True Death upon him. It’s pretty anticlimactic, but it’s also efficient, and Gown had no real reason to do further bodily harm to such an impressively stalwart opponent.
Emperor El-Nix is driven half-mad by the results of his new “ally’s” overwhelming victory over the royal armies. Climb surmises that Gazef may have given his life as a message to him, Brain, and others not to bother fighting the likes of Gown and instead building a future. Brain ain’t hearin’ it; after drinking with Climb, he’s jumping right back into the fight.
As for King Ramposa, with his eldest son gone too long and his second son already jockeying, he agrees to cede E-Rantel to Lord Ains. Princess Renner has a simple task for Climb: to deliver her handpicked roses to the memorial of the fallen armies, flashing her trademark evil smirk once his back is turned to her.
Ains’ dark forces march into E-Rantel without resistance, save a pebble thrown from an angry little boy whose father died in the recent battle. Albedo, who hates humans, prepares to execute the whelp for his disrespect, but she’s blocked by Momon.
Even weirder, however, is that Lord Ains appears behind Albedo to offer Momon a job as their law enforcer in the city. No harm will come to the innocent, as long as Momon makes sure to deal with the guilty. I imagine either Ains simply used a cloning spell or Demiurge disguised himself as Momon or Ains.
Whatever the deal was with two alter-egos of Momonga being in the same place at the same time, the effect is the same: the townsfolk see Momon as their protector, sacrificing his honor for their sake. I’m sure they’d much rather have an adventurer like him enforcing laws than the myriad undead beasts under Ains’ command.
With that, Sorcerer King Ains Ooal Gown takes a seat in the throne room of E-Rantel’s royal palace, all the Floor Guardians and Battle Maids assembled and offering him congratulations on his triumph. But as usual, he didn’t have to actually do much, and a lot of the plan that was just executed wasn’t even his, but Demiuge’s.
Still, as far as Demiurge, Albedo, or anyone else in that room is concerned, everything that happened happened because their lord and sorcerer king made it happen. E-Rantel is now the capital of his new “Sorcerer Kingdom”, Ains Ooal Gown.
No doubt OverLord IV will deal with the political transition and administration of the city, dealing with any resistance that crops up, and perhaps further expansion of the new kingdom. I’ll be here to watch, as always.