I've been watching Wrongs Darker Than Death Or Night. Is there any canonical evidence of the fate of Kira's two brothers? Other than the suggestion they are probably dead because they do not appear in the series. Have they ever been used in the novels?
They lived to be old enough to play springball with Nerys. I think that's about it. I don't recall the books ever dealing with them either, but I could be wrong.
Didn't Jadzia have a sister?? We never saw her either. Just cause we never see Kira's brothers doesn't mean they are dead. Of course, one could say that the fact that DS9 was located in Bajoran space means that it would have been "easier" for Kira's brothers to appear on the show than Dax's sister.
Earlier episodes implied that Sisko's father was dead, before they showed him being alive. It's possible that they just forgot all about Kira's brothers.
Or there was family difficulty. That she and her brothers lived through such hell... maybe they dealt with it through isolation.
Reon appears in the short story "The Officers' Club" from Tales from the Captain's Table which might be what The Soul Key was obliquely referencing.
Indeed, nothing was established onscreen about either. In the Lit, however, "The Officers' Club" states that Pohl died of malnutrition in the refugee camps. Reon is a focus character in the story, and it turns out... Spoiler: The Officers' Club ...he was either a collaborator pretending to be a resistance member, or a resistance member pretending to be a collaborator, or an Obsidian Order agent pretending to be a resistance member pretending to be a collaborator. The story is deliberately ambiguous on which it is, and indeed we never find out the whole truth. Either way, Nerys was not close to him because she blamed him for not doing anything to help Pohl. As for Jadzia's sister Ziranne, she appears in the story "Reflections" in the collection The Lives of Dax. .
Jadzia's sister didn't grow up during a deadly occupation, and there were fewer stories where you'd expect her sister to show up. Her wedding was impromptu enough that you wouldn't expect her to be able to get there, so that leaves her trip to Trill, which she'd only be present for were she on Trill. Most Bajorans who didn't escape and join Starfleet are on Bajor, and it's only a short travel distance between them. You'd think if they were alive they would have visited her time to time, unless as suggested they were on very bad terms.