Board Thread:Lore Discussion/@comment-5632187-20130119213241/@comment-6003396-20140102064457

You're right about Ceaseless Discharge. This was confirmed by Miyazaki in the Design Works interview.

I would speculate that the two unaccounted daughters of chaos are part of the Bed of Chaos along with their mother. Perhaps the two arms are what are left of the daughters' power, while the head/body would be what is left of the Witch of Izalith. Although this is never clarified, to my knowledge, so we can't know for sure. However, from Quelana's dialogue, we can at least be relatively certain that some remnant of their mother is still part of the Bed of Chaos when the Chosen Undead faces it.

I don't know of anything that states that the Witch was the mother of Pyromancy. Before Pyromancy the Witch and her daughters wielded flame sorcery. It was only after their mother created the Flame of Chaos, devouring/transforming herself in the process, that Quelana developed Pyromancy – or something along those lines. Izalith Catalyst