Ace is our main character, the son of a Mob boss in Palermo, Sicily. He is naturally kind and caring, a trait that conflicts with being a monster meant to feed off negativity.
Lorenzo is Ace's dad. He's a mob boss. He puts out a tough exterior for his underlings, but he's more easygoing and even soft around people he trusts. He has a lot of fears and insecurities, which often drive his behavior when put under stress.
Sal is Lorenzo's younger brother. His presence is threatening, and his personality isn't any different. He's well cut out to be a mobster. He's incredibly loyal to Lorenzo, and would do anything for him.
The Shadow Beast is a mysterious, malevolent monster. It gifted Ace's family with frighteningly powerful abilities. It claims it gave them everything they wanted, and deems anyone who isn't happy with it simply ungrateful. Its motivations and intentions are unknown.
Cassy is a girl Ace met at school. She's new to Palermo, having moved from central Italy. She's trying to make sense of the weird world of vampire mobsters she's found herself in.
Basil is Lorenzo's right-hand man, often acting as his representative outside Palermo. He made his way to the top in spite of his rocky past, and entirely unintentionally.
Luciana is Ace's mom. She loves Lorenzo and Ace to death. She often isn't told about mafia issues. It irritates and causes her some stress, but she rarely prods for any information.