Colonel Sato was waiting in his Knightmare frame outside the World's Requiem, watching the ceremony take place on his combat monitor. He was chief of security for the event, and it was his battle group's job to ensure that nothing terrible happened to anybody present, Britannian or otherwise. Empress Nunnally had done a significantly well job of reshaping the form of the Britannian Empire, as her father and brother had both been tyrannical dictators. Nunnally, while still an absolute ruler, was much less harsh on those she ruled. She had returned Japan to a sovereign nation, and to Colonel Takeru Sato of the Black Knights, that made her the best Imperial ruler he'd ever seen.
Sato forced his Knightmare frame to an alert position, calling out to his comrades as the King Arthur appeared. "Everybody, prepare to get in there and fight! We-" He stopped short as the Knightmare claimed to be Zero, his combat monitor changing to focus on the King Arthur, and the newly arrived Bastion. He watched in terror as Zero claimed to posses the powers of Fleija. He'd witnessed its use first hand, and was horrified that his leader would stoop so low and use such a vile weapon. Until he did, and the Bastion stood intact, only the Knightmare frame it had subdued being destroyed. It was...amazing. This truly was Zero, the same Zero he'd served for a decade.
As Kallen screamed at Zero, decrying him as a fake, Sato curled his fist in anger, his Knightmare doing the same. If this wasn't Zero, who was it? Lelouch had been killed in front of their very eyes, and he was perhaps the only other person capable of such genius, aside from his brother Schneizel, who had created the Damocles. However, Schneizel was clearly not Zero, as the two had been seen together on hundreds of occasions. Bringing up his communications, he called to Kallen. "Commander Kouzuki, there's no way that isn't Zero! He's the only one with the knowledge to do this sort of thing! He got past all of our defenses without a hitch, and that Knightmare....who else could it be?!"
Just then, the King Arthur flew overhead, and Sato turned to look at it. It was a marvelous piece of art. His mini-Fleija cannon was proof enough for the Colonel. This was Zero. The man who had brought about the liberation of Japan. "Commander...we have to listen to him. We're the Black Knights. We were made specifically to serve Zero. We have to follow him."