Omega; A young Woman with few memories wakes to find she has spent 2500 years in stasis, in a basement of scientific horrors.
Horrors that could supposedly destroy the world if ever let free. Horrors of which she was the last to get free. her shapeshifting powers are based on an understanding of what she is shaping into. So without her memories, she was helpless to escape the magically enhanced nanite swarm, so she made every cell of her body resist and infected the swarm with her own fractured mind then evolved into something greater then either being could ever be alone. her form and abilities were now only limited by the number of nanites in her swarm, and the technologies and anatomy she understands.
Rather then become an adventurer that seeks out powerful monsters to study, or a doctor who secretly studies powerful adventurers she decided to infect monsters and wasteland scavengers with her swarm, studying all, and strengthening her favorites, Like a post apocalyptic Professor oak mixed with a dark monster queen.