There seems to be no end to the battle against the Gauna at present, and things are about to take an even more uncomfortable turn for those involved in the latest skirmish of this conflict.
In short, the Gauna seems to have appropriated not only the look of Sidonia's frames, but also one of their lost pilots, namely Hoshijiro, whose voice causes much discomfort as it rings out over the intercoms of the other pilots while they try to go on the offensive against the enemy they've discovered. Although this is accomplished with some success, it seems that alongside Hoshijiro's likeness, these Gauna have additionally copied the skills of the original too, making for a difficult battle as Sidonia's finest find themselves matched blow for blow tactically by their opponent.
The appearance of Hoshijiro's likeness and voice is all too much for Kunato who, perhaps wracked with guilt at her death, loses his mind somewhat as events unfold as yet more of his comrades are lost - in contrast, Tanikaze seems determined to keep his cool no matter what, even going so far as to take a "sample" from a defeated Gauna to present to the scientists back on the Sidonia. Not that those at the top of the ship's command have any issues with cloning, as some time spent delving into the past shows us Tanizake's origins as well as explaining Hiyama's behaviour and opinions giving her pivotal role in those past events and the effect they've had upon her current place on the ship.
As a whole, this week's Knights of Sidonia got its balance pretty much spot on - its space-faring action was delightfully fast-moving and captured the stress of its fluid, developing situation excellently (right the way through to Kunato's breakdown), and its flashback material answered some decidedly important questions while still keeping enough under its hat to continue to present some sense of mystery around the Sidonia and the organisations in charge of it. I'm not entirely sure whether the show's animation quality has improved or I've simply gotten used to it, but even at its worst Knights of Sidonia's presentation seems to be far less jarring than it was initially, which is helping to power the series along in some interesting directions - I'd almost compare it to Attack on Titan with sci-fi trappings at this stage if I didn't imagine people wanting to wreak bodily harm upon me for doing so.