The World Of Twilight

Since the transition from sempa to kopa isn't necessarily voluntary - fubarnii can take chemicals to control it, but I imagine that sometimes something goes wrong - how do you think they handle the awkwardness that comes when someone's wife changes? What's the cultural script? Are you expected to be buddies? Is it supposed to be some kind of terrible betrayal and you're supposed to hate each other (kind of like how couples in our world that are trying to deal with infidelity have a lot of pressure to turn on each other even if they'd rather work through it)?

Also? I have this image that there's a fubarnii myth - or maybe an opera, do they have opera? - about a prince who's captured by a rival, so his most beloved sempa gathers up his loyal knights to go rescue him, only being in charge of so many kopa causes her to transform (of course, this story is set in the "old days" before the alchemical preparations to control the change were as reliable). What a tragedy! They sing a tragic song together (maybe in three-part harmony, with two kopa voices - do kopa and sempa have different voices? - and a sempa voice representing the wife's "old self" singing along with her former husband and new kopa self).

Thoughts?

You've certainly been doing your homework!  I think you've grasped the general complexities of Fubarnii romance... I think a progressive city-Fubarnii would be expected to accept their spouses choice to move on. Marriage to a Fubarnii is a temporary thing, but they should maintain a lifelong bond of friendship.
Less progressive Fubarnii may see the development less favourably, considering the age and seniority to be quite clear, believing that it is the sempa's role to accept their position. I would like to think that would be the exception though.

I like the idea of your tragic opera, particularly if they hadn't had chance to have jenta before he was taken.
I think they probably went on to live as Enarii (most of the ancient myths are of the old Enarii)

If you can count on me to do anything, it's to obsess over things I find interesting and seep my brain into all the nooks and crannies therein!

I really like the idea of "progress" in sempa/kopa relations. "Old school" rigid fubarnii who view "their" sempas as their property, whereas more "modern" fubarnii view it as a really personal process - you should be what you want to be. The old school fubarnii view it as a betrayal if one of their sempas becomes a kopa without "permission" or while they're still alive (or maybe even dread the idea of one of their sempa becoming a kopa and thus disinheriting a favored jenta...). Modernist fubarnii might do things like sponsoring their former sempa in business or exploration, founding new "branches" of their family tree more quickly than you can if you wait for one of your jenta to grow up and become useful!

I wonder if there's a lot of cultural differences here.
While there are probably are some subtle changes, most of them seem to be visible on the models themselves when it comes to the Fubarnii, while it's more profound on the Devanu. But there probably are far more sempa than kopa.
The Engu make a clear distinction between Sempa and Kopa, but what about the Delgon?

Also, if I remember correctly, Ronan is a sempa. But there are no Enarii jenta, which is strange.
Are they afraid to loose their godhood status if they breed?

I don't think the delgon or dhogu have a huge variation between sempa and kopa, certainly not as much as the Engu.
Roban is definitely a Kopa, as are all the enarii (as far as we know). Maybe they are immortal? This is a contentious argument within the delgon priesthood, but not something they have ever dared to raise with their gods.

Then they truly are Gods? I always thought the Enarii were a refugee people, on the run for some unknown terror from behind the wall ... sorry Setir mountains, who saw an opportunity when they first got in contact with the Delgon.
If they truly are immortal there is little doubt on who's going to be the victor of the current war.
This is however going terribly off topic.
Apologies

I think Mike has deliberately left the question of them being the real gods unanswered...or at least you get different answers depending upon who you ask. A bit of mystery is good :D

I agree, but it's never a bad thing to debate about it  ;D.

Yup, it's up for debate! It's good to go off-topic occasionally  :)