Au idea: mine

Basically it's still the same as the regular houseki no kuni but what if the lunarians were zombies instead of humans and the gems we're half hybrids of gems and humans.

It still has the story but everyone acts a little bit differently. All their clothes are very different and they uses guns as well. There is no other human alive except a group but they aren't outside a lot.

This is my au idea as far as I know. If the gems get bitten they have to isolate themselves so they don't go attacking their family and friends. Cinnabar has been bitten and is doing this so he doesn't hurt everyone else.

~Ghoulex