Admiral Gregorio is the commander of the Valuan Empire Armada's Second Fleet and a major antagonist in the Sega Dreamcast RPG Skies of Arcadia.
Gregorio was an Admiral in the Valuan Armada since the reign of Enrique's father. As Enrique was growing up, Gregorio taught the young prince about the art of combat and war, and in turn was greatly respected by him.
After Enrique objects to the Empire's imperialist policies and escapes from Valua to join with Vyse and crew aboard the Delphinus, Empress Teodora I ordered Gregorio to pursue and take Enrique back home, believing he had been "brainwashed by the Air Pirates." Though he was reluctant to fight against the young boy whom he helped raise and come to see as his own son, Gregorio accepted his orders and began his pursuit of the Delphinus.
After tracing the Blue Rogues to Esperanza, Gregorio attacks the Air Pirates but is beaten. He pleads with Enrique to return, but Enrique refuses and proclaims that he will not return until the Valuan Armada stops its conquest of other nations. After seeing that Enrique is determined to stay and joined of his own decision, Gregorio allows the Blue Rogues to leave Esperanza without further conflict, tearfully parting with his surrogate son.
After Lord Admiral Galcian performs a coup against the Empress and sets in motion his plans to take over Arcadia, Gregorio turns against the rest of the Armada, realizing that Enrique was right to be worried about the direction of the Empire. When Galcian when the latter corners Vyse, Aika, Fina, and Enrique at Dangral Island, Gregorio appears to save them and buy them time to escape, telling Enrique that the fate of Valua rests in his hands.
Gregorio died holding off Galcian's forces, allowing Enrique and the rest of the Blue Rogues to escape and continue the fight against the Valuan Armada. In a rare show of respect, Galcian personally had Gregorio's body returned to Valua and buried there.