This was a fun one for me to figure out, because not being a Homestuck, I was unfamiliar with the concept. So I went and researched it and picked apart the potential etymology before figuring out how the Cardassians would label the emotion.

First off, you’re absolutely right that kismessitude would be very present in Cardassian culture! That whole episode with O’Brien and Gilora Rejal seems to prove as much.

As far as I can tell, kismesis seems to be a combination of the words “kismet” (fate) and “nemesis.” While there is a word for “fate” in Kardasi, aThela (ah-thay-lah), it’s a very old word that’s probably not best used widely–too much like religion. Likely, though, it had something to do with the original name for the concept.

Instead, I’d suggest a safer alternative to be tase’arget’er (tahs-ay’ahr-gayt’ayr). Essentially, it’s the opposite of love (e’ being the prefix for [at least outwardly] loving relationships and tas- negating it), and features eternal (’er) arguments (arget). Whether those are arguments or arguments…probably depends on the people involved in the kismesissitude.

Thanks for a fun question!