Sacrum Vindictae.

The story centers around Nathaniel Nucci, who leaves the military when his wife becomes pregnant hoping to lead a "normal" life. All is well for 13 years until his wife and child are part of collateral damage on a botched Mafia hit. Blinded by rage, Nathaniel infiltrates the Mafia organization responsible for the murder of his family. He ultimately becomes a contract killer for the head of one of Philadelphia's largest Mafia families, while keeping his identity hidden.