The Arcane Brotherhood

Background
The Arcane Brotherhood was a mercantile company and wizards' guild that operated out of the Host Tower of the Arcane in Luskan. The organization was very mysterious, as even its most high-ranking members were unknown, while others were very well known. It was known that their primary plan was the political and economic control of the North of Faerun.

Interactions With Mystic Obscura
While Mystic Obscura never saw the Arcane Brotherhood, they did in fact encounter the aftermath of one of their battles with the Ice Giants, having destroyed a assailing ship and apparently killing all on board.

When looking for information regarding The Black Lodge's position near Luskan, Mystic Obscura met with a woman who promised to help them, and led them up to one of the highest floors of the chamber. She offered information, in return for Balasar's staff. Balasar, magically possessed by the staff, refused and killed her, with the help of the staff and to the shock of his companions. The group fled, but not before alerting one of the guards who didn't believe their lies.