Good for the Tapai.
Sikyal has the food thing covered. Dalvor focuses on the rest. He explains that he doesn't want to offer to distribute the wing contagion until after the war stops, because introducing it beforehand would tend to give the Tapai an unfair advantage and he doesn't want to do that. He suggests that there should be a formal agenda for aid, trade, and interstellar diplomatic agreements. He calls a meeting with the Ceirene governing council. The Ceirene governing council is a bit put out that he went off and made first contact without them, but accepts his subtle hints that he was heading off a probable ruikni catastrophe.
The Ceirene governing council is alarmed to hear about the plight of the red caste. Some of them want to demand that the people of Kadrixi-4 abolish their caste system before receiving interstellar aid. Dalvor points out that they're not likely to do that. He suggests instead that there be a general freedom-of-movement agreement allowing anyone from any society to emigrate to any foreign polity willing to take them in. If Ceir wants to help the reds, Ceir can host red refugees. Ceir says they'll think about it.
Miuka and two dozen other relevant specialists work together on compiling an extensive report describing the differences and similarities between human and ruikni societies.
Ruikni have much lower crime rates, probably thanks to an underlying psychological difference! Humans have much higher cultural diversity, for related reasons! Neither of them has castes! Ruikni are very very serious about hygiene and safety! Humans have much worse technology (although they're catching up fast) but much better-developed magic; there's a theory that contact with humans is the only reason why ruikni picked up any magic at all, which ruikni theorists find unsettling for reasons of lingering xenophobia, but the fact that there doesn't seem to be any magic on Kadrixi-4 supports the idea pretty strongly! For an in-depth explanation of magic, see Appendix 1! For a condensed history of the human-ruikni war, see Appendix 2!
Here is an explanation and comparison of the ruikni post-transition government, the Ceirene governing council, and the Aluvai hereditary monarchy! It mentions that King Dalvor is a little over five thousand years old by his local calendar, approximately twelve hundred and fifty by Kadrixi-4 reckoning, and references another appendix which summarizes biological differences like lifespan. Humans live about a hundred Suranse years, each of which is about one Kadrixi-4 season. Ruikni live about a hundred and thirty Old Homeworld years, each of which is also about one Kadrixi-4 season. Members of either species who carry the wing contagion and successfully get their wings (see Appendix 1) will remain healthy adults indefinitely, although they are still susceptible to accident, violence, and sufficiently serious illness.
Appendix 2 explains that the ruikni found Tseiza-3 tens of thousands of years ago, drove the humans into hiding in a network of Spheres (see Appendix 1), and then carefully explored the maze of Spheres through the remaining portals until they finally found their way in to Suranse, where by that point the humans had forgotten they ever lived on a spherical planet. (See Appendix 4 for an explanation of Suranse cosmology.) They continued their efforts to exterminate humanity for another hundred and fifty years, until King Dalvor suddenly acquired an immensely powerful magical ally and terrified the ruikni into near-total civilizational collapse, whereupon the Cult of the Destroyer on Ityen-6 took over in accordance with their private prophecies and established reasonable diplomatic relationships all round.
Equipped with this report, a representative from Ceir, Sikyal's handpicked logistics team, four competent translators including Tebrel, and a more concrete diplomatic agenda, Rain in Starlight returns to Kadrixi-4.