Guo-Radha

https://wiki.rpg.net/index.php/Forgotten_Realms_(The_Time_of_Troubles)#NPCs

What we know

From Mielikki's Animals

"My murder-mates and I have traveled to bring you the news you seek. Guo-Radha's scryings have not discovered you yet - she has been confounded by your friend's efforts. But her tulpa has returned to her and brought news of you. She plans to have it reinforced and ordered to track you down. But much has kept the Zulkir of Divination busy. She is still adapting to the divine power she holds, and her lust for power has driven Thay into a civil war that threatens to spill across the borders. Her forces have defeated the Zulkirs of Invocation and Illusion - the nation's most devout followers of Kossuth and Leira, respectively - and she has used the powers of Command that were once Tyr's to press-gang the churches into her service. The other zulkirs are trying to combine their efforts against her, but infighting, the disruption of the magical Weave, and the erratic behavior of the undead forces of the Necromancy Zulkir, Szazz Tam, is holding them back. This seems like a situation that will get worse before it gets better.")

From Lefaric's Journal

Later in the journal, Lefaric is thrilled to mention that the goddess has chosen him and other high-ranking Guildmasters to bear a portion of her power, so that they can bring healing (at a price) to those who need it. He is sent east to build alliances and support for the church and the Zhentarim, who have become increasingly intertwined. The goal of acquiring service contracts (in the form of "Indulgences") from the Nar was secondary, the primary goal was to make it to the "now vulnerable" capital of Thay, where he would meet with a Zhentarim attache named "M. Corbulo", and he and the Zhentarim would work to form an alliance with a wizard who has acquired Tyr's power named "Guo-Radha"

From the Thayan Currency

Since the Troubles, Thay has been embroiled in civil war. With her newly-stolen powers from Tyr, Guo-Radha, zukir of Divination, has betrayed her "fellow" Red Wizards with the goal of conquering Thay for herself. She has already slain the zulkirs of Illusion, Invocation, and Transmutation and grabbed control of most of Northern Thay, including the capital city of Eltabbar. Eltabbar has gone under lockdown, where the paranoid Guo-Radha has turned it into her personal fortress. Any who approach the city without her approval is annihilated by her magical defenses.

The remaining zulkirs have disowned Guo-Radha and are united (at least as much as Red Wizards can be) to stop her. They are led by Szazz Tam, zulkir of Necromancy and most powerful of the lot. He and the remaining [I]zulkirs/[I] are said to be holed up in the fortress at ThayMount (Thay's central mountain) and directing their opposition from there. The lands on the borders of their territories and around their walled city are patrolled by Szazz Tam's undead legions. Their behavior seems to be rather erratic as of late, however. Many of these undead seem to slip free of the control of their mortal handlers, or even directly contradict orders they are given. The Red Wizards lose territory to Guo-Radha that they should be holding on to, by all rights, and the reclusive zulkirs provide no answers.