Nero is the main protagonist in the fourth installment of the Devil May Cry series. He's also proved to be Vergil's son. Nero serves as a Holy Knight in the Order of the Sword, a religious group that worships Sparda and fights to protect the world from demons. Kyrie is the childhood friend of Nero, who he shares a strong romantic bond with; this romance plays a major part in driving Nero throughout the events of Devil May Cry 4.