Nero is the don (boss) of the Omerta family. Unlike his right hand man Big Sal, Nero is mostly absent in the presence of the general public, instead coordinating the shady operations of the casino from the privacy and comfort of his own hotel room. He does not appreciate callers violating his inner sanctum.
How Little We Know: If the player character sides with Cachino, then the Courier will end up killing Nero as a result of the quest. Cachino then takes Nero's position as leader of the Omertas. Nero is also Caesar's puppet behind Operation: Racket, the operation for the Omertas to kill civilians on the Strip in order to take it over.