@Tfmonkey I've concluded that celestina is a necromancer with a decaying pet monkey. That's why the colors of the monkeys is never consistent. It's either melting off or decaying (blue).
The extra hands and limbs are all part of the souls she has absorbed after operating for thousands of years. Now we see her in the modern era visiting an unsuspecting victim whose life will be used to restore the decaying flesh of her beloved pet who she promised she'd never abandon.
I figured it all out, bud.
@Tfmonkey Tzeentch blessed your waifu!