A couple of thoughts concerning the current chapter, and Furuta’s seemingly easy defeat of Eto. There are several factors that probably played against her in this battle, much of which likely involved her own over-confidence.
Prisoners are drugged with RC suppressants as part of the Cochlea’s improved security. So most likely, she would have been no exception to this standard procedure for prisoners.
We also don’t know how long it had been since her last significant meal. That Editor Pate she was served likely didn’t count for much, though she claims it gave her a boost.
She’s also an Ukaku, which has an inherent weakness of burning through RC cells quickly. Imagine how much would be needed to generate such an enormous armored form. Her overconfidence meant she probably never considered the need to ration her supply of RC cells, the way most Ukaku do. She usually doesn’t need to, and counts on the overwhelming force of her armor. So when she was caught off-guard, and her armor destroyed……how much reserves did she even have left?
Beyond that, we know Rize’s kagune is special. V wanted her back, Dr. Kanou wanted her for his experiments, Furuta wanted it for himself, and Aogiri was hunting her and took Kaneki because of it. Which means that Eto wanted it for some reason, and showed no surprise or anger over her loss. She merely confirmed her suspicion that Furuta had Rize’s kagune, and proceeded to prod for more information.
Does that mean that Eto already knew, long before now, that Rize’s kagune was a potential threat?
Either way, she clearly had no idea that Furuta was anything but human. She went into things simply considering him another Investigator, and got completely blind-sided because…..well….Kanou lied about how many successful experiments he had. He managed to keep that particular aspect of his partnership with Furuta from Eto, in spite of her being aware of the two working together.
But either way, it seems like factors were piled up against her and she went into things counting on brute force over fighting smart.
Even so, it seems like neither party is done. Furuta has his own plans, and Eto knows several new details to work with. She knows that he’s another Eater-type OEG, knows that Kanou lied and concealed that particular detail from Aogiri, and knows that Furuta has no loyalties to V. She also knows that in spite of his strength……he still fears being exterminated by his superiors.