Using simulacrums to keep the party on the trail to
1) kill off her rivals in the Way (Vrood, the Grey Friar, the Witches of Barstoi, and Lucimar as well as just generally doing a bit of "house cleaning").
2) retrieve the Raven's Head (which she knew thru divinations would be recovered by Heros - so she get's them to hand it to her "for safe keeping").
3) Distract/Placate the Order of the Pal. Eye - getting them to assist in getting Her to the right place at the right time, with everything she needs...
4) Thus using the strengths of those against her to assist in her ultimate victory... (insert BBE speech here)! (Evil Laugh!)
In other words - leading to the big reveal at the end where they find out they have been played all time, and they assisted in bringing back the Tyrant, and creating his new Queen... unless they can stop her...