Upon returning to Gilgamesh with news of their great losses, he concedes that sacrifices are necessary in any war. Losing Ushiwaka and Leonidas wasn’t in vain: Uruk still stands, and they now know that Gorgon is a seething mass of anti-humanity rage can not be bargained with. They also learn that the only thing she fears is the other two goddesses, and Gilgamesh recognizes that as their path to victory.
With Gorgon out and too little known of the Jungle Goddess, that leaves Ishtar, the pseudo-servant who uses a human girl as a vessel. Gilgamesh is amused by the prospect of the alliance crumbling from within, and Ishtar is by far the easiest to turn to their side, because she can be bought off with physical riches. Gilgamesh does not want for those, and is prepared to offer up to 30% of Babylon’s treasury to Isthar in exchange for fighting for them.
When Ritsuka & Co. reach her ostentatious palace atop Mount Ebih, Ishtar rejects the idea of further “collusion” with humans, lest it damage her dignity. But in the middle of battling Mash and Ana (whom it’s strongly implied could be Medusa, the youngest of the Gorgon sisters), Ritsuka tosses a cloud of gems up in the air, dazzling Ishtar, then lays out the arrangement they seek with her.
Unable to resist the lure of the pretty gems, and having never received such a large offering from humans before, Isthar folds, agreeing to join them. After assuaging Dr. Romani’s ethical concerns about who and what she is (essentially, the human girl she was became Ishtar, rather than became possessed by her, and they are now one) her 70-30 personality split is tested when she gets some time alone with Ritsuka just before dawn.
Ishtar presents a much friendlier, more human side with Ritsuka than all their previous interactions, to go along with her already established tsundere nature. At first she asks if it was “love at first sight”, but when Ritsuka doesn’t understand she drops the matter. Simply being with humans has shown her that not all of them hate her, but she’s still skeptical of a world ruled by humans and not gods.
That’s not because it means her power as a goddess will diminish, but because she simply believes humans will have, at the end of the day, easier, less painful lives, compared with a human future of knowing all the answers. It’s not that different from wanting humanity never to leave the Garden of Eden: more knowledge, more problems, more despair…but more freedom and opportunity too.