Phantom Zero is one of the Four Guardians in the Rockman Zero (Mega Man Zero) series, serving as a major antagonist. Phantom is known for his ninja-like abilities, exceptional speed, and mastery of stealth and illusion. Loyal to Copy X, he opposes the protagonist, Zero, in defense of Neo Arcadia. Despite his antagonistic role, Phantom is depicted as honorable and steadfast, and his ultimate sacrifice leaves a lasting impact on the story's progression and Zero's character development.