GAvillain

So, the concept of Grimhilde surviving the end of Snow White and the Seven Dwarfs comes from Romano Scrapa's Return of Snow White comics that I personally take as canon.

The comics don't really go into detail as to HOW she survived her defeat in the film, but that death/defeat very clearly afflicts her with her falling into a death sleep that can only be revived by sleeping on coal.

She restores her powers somehow later on in the comics and no longer falls into the death sleep. It's never really specified if she just survived her fall, if she died and brought herself back, or whatever, and I haven't really expanded on it in the story yet either.

However, because Quite a Glittering Assemblage is a crossover that includes Marvel, I tend to think of it in terms of one of my favorite Loki moments. Balder decapitates Loki at one point, and you think Loki has died. But at the end of the issue this happens:

"The first thing a sorcerer of quality learns is to make himself as difficult to kill as possible."

High level dark magic users like Grimhilde and Loki have magical protections that make themselves as resistant to bodily injuries as possible. It takes more than mortal means to do them in. Loki, as a god, is obviously MORE resistant to death, shaking off a beheading with only a few days of a stiff neck, whilst Grimhilde falls into deathlike sleep periodically until she manages to restore her full powers, but the principle is the same.

Normally, it takes potent magic to kill a sorcerer like Grimhilde or Loki, and even then, in QAGA lore, there are means of resurrection through the powers of darkness by possessing another body and forging it into your own, showcased by Corypheus in Dragon Age: Inquisition:

And, if all else fails, there's always Hades or Maleficent to hand out resurrections. So death usually isn't an obstacle for most Overtakers; it's when they get trapped in magical prisons that it's really a problem. But I digress.