The Orzhov Syndicate is one of the ten Guilds of Ravnica. The guild is made up, predominantly, of lawyers, politians and businessmen and women. Though, sometimes, the Orzhov seem to come across as evil with no regard to the law, the syndicate is actually in place to keep a check on the law's reach and protect the rights of citizens to challenge any charge in a court of Ravnican law.
After leaving Origin Earth, Mark and Luke travelled to a world they believed to be Ravnica, and arrived in a church that was potentially Orzhovian. They didn't spend much time investigating, as they were needed to quell a battle between Liliana Vess and Garruk Wildspeaker outside.