The overall opinion appears to be that Marcone is a vanilla mortal who displays extraordinary tenacity and cleverness without any supernatural lineage, magical advantages, or other paranormal attributes. There could theoretically be something about him yet to be revealed, but the absence of it showing up in a soul gaze and the lack of reference to such a trait from a third party seem to indicate not.
Marcone has a large shadow. Underworld lord, Freeholding lord, etc. He has big ambitions. These ambitions tend to be realized long term. He can't be the only one to think big like this, though. Are there other Marcone equivalents across the globe? Mortals who have built small, clandestine empires that interact with the supernatural on a regular basis? If not, why? What's different about Marcone?