Nenya Kanadka

The soulmate AU that I am never going to write would really be a reincarnation AU. It would be a long, complex poly story that started out Jeff/Cathy in the present day, then turned into Cathy/Valen in the past, then Cathy/Valen/Alyt Kayinn (where everyone is sleeping with everyone, which would be totally normal for the Minbari but the part that would weird everyone out would be that Cathy is an alien, thus leading to lots of social/cultural conflict and so on that I would probably make someone else write or at least brainstorm with me). Lots of slow burn development on first the Cathy/Kayinn side of the triangle and then on the Valen/Kayinn side, and then figuring out how to make a relationship work between a time-travelling trans-species military strategist, his on-again off-again civilian explorer fiancée, and the Minbari warrior captain they both love. Also sex, awkwardness, and the occasional shouting match, mostly on Kayinn's part.

Also there would be lots of plot with the Shadow War (various battles and what all) and Jeff figuring out how to be Valen and inspire all these people to greatness, and also deal with the cult of personality that's accumulating around him. Having his partners with him would be a huge help, though. I think they eventually have kids, because canon says so, but I haven't figured out if Jeff and Cathy would be able to have kids or if it would need to be Valen and Kayinn. (I think the latter.)

Eventually, sadly, Cathy passes away, and sometime after that Jeff loses his other wife as well. And then as he thinks he's winding down in his twilight years--he's not old, but he feels like it--the Vorlons throw him back into the present.

Which is when he finds out that the sneaking suspicion he's had all along that Kayinn was Delenn in an earlier life is actually true. And the last part of the epic tale is Jeff/John/Delenn, or Jeff/Delenn after John goes to the sea.

It would be a deeply moving and romantic sci-fi book, if I ever wrote it, which I won't.