Dormant. It takes place after an apocalyptic war and the discovery of E-Ther, or life force, which was used as clean, renewable energy. E-Ther power WMD's, designed to target biomass while leaving minimal structural damage were used, and weaponized is a sort of evolutionary steroid in the long run.
The world isn't all ruins like Fallout, most cities are completely intact and functional, yet they 'sleep', unresponsive in the absence of the Sage computers. Accelerated growth and schizophrenia in the eco-system and wild life, thanks to the erratic E-Ther flows, has created a beautiful, wild, untamed world, brutal and surprisingly sophisticated.
It takes place hundreds of years after this war. Human cities have gained a foot hold, trade and commerce recommence, E-Ther waste products are mined as fossil fuels, and people build with scrap when the greatest technology on the planet surrounds them. Religious sects believe it is ashamed of them, and the world will awaken when they have matured.
There are many different options for a playable character :) One I've used (just for an example, I'm more then happy to help you adapt a character into the lore) was a Sage II, a bi-product of a failed experiment, someone descended from the human test subjects of the Sage II program. Has a mental connection with all Old World technology around him, but limited control. Could Awaken ancient vehicles, for instance, but actually using them was somewhat like taming a wild animal.
Had two weapons, a lance and a grapple. The lance was a simple long metal pole made of Tenusteel, a 'programmable metal' that can take limited shapes, in this instance extending and retracting. Could be charged with a red hue that sheered metal like paper. The grapple did not have a hook or a pulley, but a block of Tenusteel that would form into threads and weave together upon firing. Because of his Communion (Sage like telepathy) the Tenusteel in both objects could do more then it was designed for, not being restricted to preprogrammed routines and instead becoming like a living part of him.
The grapple could move like a muscle, twist and thrash and bend, tense and loosen, and form into any kind of hook or claw, whatever was needed, meaning almost any structure could be climbed with ease. However, it contained a Shadow, or multiple Shadow's, imprints of past users energy. while usually just feelings or thoughts, this one was capable of will and speech, and the weapon passed from hand to hand, corrupting it's users and making the Shadow more powerful. Think of it like the ring in LOTR. There was another Shadow, however, in the grapple, which was kinder, and weaker, and tried to be a focus for him, so he could keep the corruption at bay. But when the lance won out, it could change the grapple, turning it into a deadly whip with hundreds of fibres ended in needle like energy hooks, which could tear through armour, flesh and bone in a gorey mess.
That was the character I used ^^' if you want to try a Dormant CYOA, PM me and we can discuss your character :)