This may have been addressed elsewhere, but Marcone seems to be of abnormal interest to the supernatural community. He's the only Mortal free-holding lord of the Unseelie Accords. A Valkyrie is in his service, and Monoc Securities seems to have a vested interest in him. He's made deals directly with the Queen of Air and Darkness.
Now, I like the idea of Marcone just being a regular mortal. Extraordinary in character and accomplishment, but still vanilla. However, he's displaying the same level of impact in the world that we see with the likes of Harry Dresden, Knights of the Cross, and Fae Nobility. I don't see other vanilla Mortals in the series with the same level of impact, apart from Dresden, and to a lesser extent with the Paranet, Elaine Mallory.
Has it been confirmed that Marcone is a Starborn? It would seem a little too obvious, and possibly redundant, but his signature seems to match the profile. If he's not a Starborn, is he really just a remarkable vanilla Mortal? Or is he something else?