Rare or self made trope

Basically every so often I remember about Cakeverse and wonder how someone came with idea to twist ABO into it. I'm wondering if you saw something similar, twisted trope that became their own category or if you came up with something of your own.

I honesty was thinking about trying to do something like this but as expected it's much harder than it looks. Still would love to try in future.

I hope I put good label on post, let me know if it need changing.