The Obsidian Syndicate

The Obsidian Syndicate conducts its shadowy operations from the bustling freeport, Port Obsidian, where there are no laws but the honor among thieves. Port Obsidian does have a local law enforcement but they stay on the side of caution only intervening when necessary for fear of retaliation, giving it a sense of lawfulness. The Syndicate has woven an intricate web of power, conducting its dark dealings within the hidden depths of the port.
The Syndicate is led by an enigmatic entity know only as The Ebony Serpent. Their true identity is only known amongst few of the highest ranking in the syndicate. Under The Ebony Serpent's cunning leadership, the Obsidian Syndicate has evolved from a small ring of smugglers into the most powerful black market organization. They have leagues of pirate factions, smugglers, bandits, and even some townships working for them. The web spins so deep that a lot of the organizations that work under them don't even realize it.
There is a unique form of communication for the syndicate, with their dark dealings they've uncovered profane dark magic which allows them to covertly mark targets that they wish to track for investigation, kill, or monitor. They also deploy these marks on various landmarks to denote safe houses, meeting spots, potential threats, or lucrative opportunities. The marks can only be read by those who have been trained in their dark magics and they hold the knowledge of it very close. The Night Lords are the ones who train the others in the marks that they allow them to use and most don't even understand what it means, as an example a bandit may be taught to cast a spell to mark a lucrative opportunity but wouldn't know the spell to see the mark and must fully trust that the syndicate will follow up on the mark. Each mark can be traced back to the caster through the code given to each caster, making each casters set of marks unique to them. By having the unique marks it allows them to clean house of any leaked knowledge and punish those who have done so.