Constantine, I had some thoughts on the issue:
* Reflecting what has happened, we could somehow cut the Fissoan crest in half, and one side will be Fissoan, the other Madinian. The missing half will then be filled in with only a neutral colour clearly showing a meaningful part is missing
* alternatively, maybe Fissoa should continue using the existing crest, and we'll come up with something new. I have some plans in the works, and a new banner would probably be needed anyway.