Ok. That was obviously a weird read... This isn't really a sequel, is more like all of this happens at the same time as the first series.
I haven't really watched the anime adaptation, but judging by how people rated it and the comments on MAL it's obvious that THIS WASN'T the part that was adapted.
Having said that... It'll take some time to put my thoughts in order... Essentially because I'm not sure about what is really the stance of the series on queer identity. For example, it's the plot a loophole to show some yuri-scenes and soft-yaoi scenes? What it's wrong about considering homosexual relationships between girls (or boys for that matter) to be normal? Is it really just about the "That's nature's way" or is there some other message behind? It's the "blood getting thinner" thing a cheap trick to justify the idea of needing males to reproduce even when they've developed a third sex (Not gender, author there fucked up) rendering males unnecessary?
Why would you include a misandric character as the main villain?
I won't answer all this questions, partly because it's 2 am. Partly because despite all that I enjoyed the ride.
Welp, I'm ready for the third part. It cannot be crazier than this