Board Thread:Lore Discussion/@comment-26894987-20160408114759/@comment-4511886-20160408123233

Quelana disappears if the Bed of Chaos is defeated before you meet her, or when she teaches you her last pyromancy, at which point the Bed must be dead, anyway. This would imply that she wants to end her family's "suffering," which she eventually requests the Chosen Undead to do.

With the Bed of Chaos dead, the Witch of Izalith, or what's left of her, is also killed. On top of that, it can be assumed that most, if not all, of the Daughters of Chaos found throughout the Demon Ruins and Izalith are slain by the Chosen Undead on their path to the Bed.

The whole modern-to-ancient language theory seems kind of backwards. Oswald and Alvina, for example, are continously in contact with other characters that speak "modern" English, yet they don't speak that way.

My guess is that people with some kind of authority, such as Oswald (Pardoner of Velka), Dusk (Princess of Oolacile) and Alvina (covenant leader), use words like "thou" and "art" instead of "you" and "are." Quelana probably doesn't see her as having authority over the Chosen Undead, even if she becomes their mentor.