From what I understand is that she went to the dalelands but why!? Any canon reasoning? The pcs should have to find her in my paragon tier but I'm not sure what to do with it
Supposedly, she's laying low in the Dalelands, after some vague clash with Velsharoon or something of the sort. She most likely keeps in touch with Elminster, and may even dwell with him in Shadowdale (maybe not all the time, but still). The Simbul lost a great deal of power with Mystra's death; since El was (perhaps still is) her lover, it's no surprise she'd want to go to him as the world falls apart around them.
Tell me, is your group focused around Aglarond or the Dalelands? If it's the former, perhaps the hook could be that a former servant of the Simbul who survived the century of destruction wistfully recalls her time with the Simbul, and mentions how while most think the Simbul died, she is sure her former mistress is still alive, and traveled west, to be with someone dear. If you're in the Dalelands, maybe a group of Dalesmen/merchants/travelers spotted a silver-haired witch in the woods, who was dressed in rags and seemed mad. Hope this helps.
I also replied in your FR Bane thread. If your ultimate goal is to destroy Szass Tam, perhaps the PCs learn in paragon tier about the Simbul, and seek her out, learning of how she was the only spellcaster Szass Tam feared. At the end of paragon tier, your group finds her, but her power is a shell of its former glory. In Epic Tier, your PCs ally with the Simbul and seek the aid of Bane/his church; united, the three parties move against Szass Tam.
It helped alot actually thanks. My campaign is gonna start in aglarond and is going to mostly going to be undead based. (thay and szass tam and maybe bane)
My own campaign is based in Aglarond and Thay, too. The group first began working against the Stone Bears and earned the gratitude of the Simbarch Council, notably one who turns out to be the Simbul's half-elven son. The group continued doing odd-jobs for the Council for a bit before they were asked to infiltrate the encroachment of the Thayans. They went to Citadel Dantalien and established that fortress as their temporary HQ, before they began scouting the area for Thayans and spying on Undumor. After slaying countless undead, the group secured enough information, only to find the undead had dug a tunnel under the River Umber. After helping the defenders of Dantalien repel that attack, they spoke with the officers stationed there about a counter-offensive. The attack was carried out, and the Thayans were driven from Undumor. But plans were recovered which shows Thay's expansion into Aglarond has been a feint, and that Thesk is the real target of Szass Tam's designs. Now the group heads to Thesk, to see what the Regent of Thay is up to in that land.
I really enjoyed the Haunted Lands Trilogy.
Was this before or after the failed Ritual of Un-making? Thats if you are using it in your game.
I really enjoyed the Haunted Lands Trilogy.
I can't tell if you're talking to me or the OP. I'm going to assume it's the OP, but in case you meant both/either of us, I did include Szass Tam's ritual in my game, but changed up its nature. Instead of undoing creation, I changed it so that if the ritual were successful, it would have unleashed a major wave of negative energy across the Unapproachable East, transforming everything into undead, under the control of Szass Tam. I find it a bit more interesting than "remake everything in my image". ST would've been the necromancer lord of a huge chunk of Faerun, not the alpha and omega he was being set up to be with the RoU.
As for the Haunted Lands Trilogy, I really enjoyed the first two books, but the third one kind of left me ambivalent. The time jump from between the second and last books caught me off-guard, and I hated how Aoth was kept around with the deus ex machina that is the "spellscar of longevity". He was my favorite character, but I wasn't happy to see how he had survived the past century or so.
Now if it is random tomfoolery, well you get the point. :P
I like your Idea better anyways LM than the book. That sounds
. Makes me think of Mordor. Then again I am reading the Ring Trilogy, so it is fresh on the mind. 
If I post after someone and do not use the "Quote Feature", it is me asking the last poster. Now if Drizzty:P goes and posts before me, then I edit it with the post I am asking about. :D Now if it is random tomfoolery, well you get the point. :P
Just making sure.
I like your Idea better anyways LM than the book. That sounds
Thanks.:D I was trying to figure out a way to make Szass Tam a major threat strictly on the material plane level. The whole RoU, was for me, just way too much. The whole idea that someone figured out how to undo everything, it goes "missing", and centuries later it winds up in the hands of a specific, well-known antagonist with a newly-revealed, unrivaled ambition to undo everything (with the exception of your Lady, of course:plotting
just broke the deal. I always preferred the notion that Szass Tam was content with his place, and wanted to be a god amongst men in terms of magical might (and not divine, reality-reshaping ability). The Haunted Lands Trilogy just took my image of Szass Tam as a unique mastermind and made him a generic megalomaniac, one of my biggest gripes with the trilogy. Other than that, I can't find many other things to complain about. What did you like/dislike about the trilogy?