Tower of Nora
The Tower holds the governing body of Nora - a sort of councilship of leaders looking to further the city's goals.
Originally a guild of merchant leaders which governed the many merchant companies that resided on the island, they sort of coalesced into a government.
Try their best to be anonymous, some might use their power publicly to further their own ambitions.
Dune esque like those spacemen looking guys who visited Arkades planet white robes covering faces?
Maybe a super stylized Burhka look - jewellery to cover face sometimes?
To be able to join the Tower is through an invite only basis, must become prominent enough to be able to join.
Maybe will never confirm if someone is part of the Tower or not?
Spacing Guild from Dune:
The power of the Guild is balanced against that of the Emperor as well as of the assembled noble Houses. Essentially apolitical, the Guild is primarily concerned with the flow of commerce and preservation of the economy that supports them. Although their ability to dictate the terms of and fees for all transport gives them influence in the political arena, they do not pursue political goals beyond their economic ones.