Nezzar the “Black Spider”

Nezzar is an evil drow wizard and primary foe of Season 1 of the Owl Friends. Unbenowst to the heroes, she was one step ahead of them the entire time. She spied upon the party from the rooftops of Phandalin the moment they arrived with Sildar Hallwinter. Only Molly noticed her skulking in the dead of night.
Nezzar's plan from the beginning was to locate Wave Echo Cave, re-start the Forge of Spells, and ultimately become a Magical Arms Dealer the likes of which this region has never seen. In order to accomplish this grandiose plan, she needed to put several pieces in motion simultaneously.
She persuaded King Grol to waylay western section of the Triboar Trail region, gather supplies to aid in her efforts, and capture Gundren Rockseeker in order to secure his map. In exchange she promised sovereign protection of the Cragmaw Clan plus supplies and assistance in rebuilding Cragmaw Castle.
Next she recruited a group of Brigands led by Brughor to waylay the eastern section of the Triboar near the Long Road. She provided maps and equipment so they could establish an outpost at Wyvern Tor. They were to keep 50% of their looted suppplies while sending the rest to her ongoing efforts in securing Wave Echo Cave. In exchange she promised them first picking rights of the treasures recovered from Wave Echo Cave.
Convincing Iarno “Glass Staff” Albrek to form the The Redbrands was easy enough. She needed him to keep the watchful eyes of Clint and the local do-gooders away from her business, as well as relay information about the coming and going of Gundren Rockseeker and his two brothers. In exchange she would provide him the legal aid needed to take over the town and its holdings for his own use.
Through research, she learned that the Dwarven key required to re-start the Spell Forge had been secured by Anar Menel acting as an agent for Gundren Rockseeker. She disguised herself as a clever rogue named Liriel and "helped" the Owl Friends in combat at Ashen Sanctum. There she offered the Amulet of the Beast Whisperer in exchange for the Puzzle Box and its contents. Acting faslsely as an agent for the Emerald Enclave, she tried tricking the party into handing over that key. The keen eye of Sparky BaneDusk saw through the ruse and, once discovered, she quickly cast the Teleport spell.
Her plan to reclaim Wave Echo Cave wasn't without its challenges. Though she secured the Temple of Dumethoin in the northwestern section of the old mine, the eastern section proved a more difficult task. Several undead threats lurk there, along with a fungi cave which she daren't enter. Her attempts to negotiate with Mormesk the Wraith proved dangerously unsuccessful. And she feared the Zombies and Ghouls, which viciously protect the old mine against outsiders. She summoned a Life Domain Cleric with a penchant for Necromancy to help her clear the chambers. But they either backed out of the deal or were otherwise waylaid.
Update: The Owl Friends entered a pitched battle against Nezzar and her ally Iarno “Glass Staff” Albrek on 23 Kythorn, 1491 DR. Before being felled, she broke her Spider Staff, transforming her Drow form into a Drider Witch, her acursed form sitting atop a Huge Spider's body. The battle led to a chamber in which Nundren Rockseeker was being held. The battle ended in victory for the party, with piles of spider viscera and goo staining the walls of Wave Echo Cave.