Interesting, a Fallout setting.
But Ten Thousand Years
Even so, it sounds interesting enough.
I can see a few ideas.....
Does it have to be the Fallout Shelter Survivors, or can it be the stuff that was on earth when the bombs hit?
1) Today's nuclear weapons have then ten thousand year fallout potential the war that caused this scenario the large ammo dumps of these things, Around the world, were opened and detonated.
2) Some humans were not able to get to a fallout shelter. and were forced to to try and survive using Fallout Filter Masks. But soon those failed and the began to 'evolve' into a new type of human, 'Aurian's'. The Aurian's Are able to manipulate the aura around them like tentacles. they can use their aura in all things; Work, Battle, Pleasure.
3) I am thinking of using the the Big Eyes Small Mouth system or the freeform format.