Marius Kent

The Baron of Kent. Marius earned his barrony by killing the people who held it at the time when they refused to back Arabell of Alantaine in his quest for the throne, and then serving as a general in that war.

A person mentioned during a conversation between Kristov and another member of the Syndicate, the implication of the conversation was that the Ash Syndicate is trying to make some sort of deal with him or convince him to do something. The details were somewhat vague. It matches with what Fox told us, and with Alice’s identity.