She's a sword! Specifically, a legendary blade passed from hero to hero. Eventually, she gained a humanoid form, through mysterious means which I haven't really thought about yet, so they shall remain unknown.

Her true power is contained behind 100 layers of restraint. By removing the 100th layer, she can draw a single blade from its sheath. By removing subsequent layers, her power grows exponentially, and she can wield thousands of swords telekinetically