A mysterious teenager of unknown heritage and characteristics. He appears as male although his true gender and age remain unmentioned. Somehow like Arianrhod, he somehow manages to preserve his youth where said he has not changed in over a decade. His left eye is always covered by his green hair, with a tattoo on his left cheek. Always wearing a red-purplish tuxedo with a light blue undershirt and a yellow ribbon necktie.
Other than appearances, Campanella is a mysterious individual whose true self is concealed by his mischievous facade. A cold-hearted person who enjoys teasing and tormenting other for amusement, much to the pity of a certain jaeger wannabe.
But as an Ouroboros member, his loyalty is faithful directly to the Grandmaster only, while overlooking the other Anguises and Enforcers, as he watched Weissmann perished without assisting his superior.
Campanella is one of the recurring enforcers of the enigmatic Ouroboros appearing in each story arc of the Trails Series. His role as No.0 was to observe the projects in the organization's master plan, and report the outcome to the Anguis echelon. After his objectives were fulfilled after the Gospel and Azure Zero failures, he was assigned by the Grandmaster to deal with Giliath Osbourne and recover the Phantasmal Blaze Plan.
- As the No.0 Enforcer, he is the only enforcer mentioned to report directly to the Grandmaster.
- He was the first and only character who has broken the fourth wall as shown in the Star Door 14 side-story, where he turns to the screen and warning the player about "peering".
- His hobbies are quizzes and Pom'tto as his character is shown in the minigames.
- Until CS3 was unveiled, Campanella is the 2nd Ouroboros Enforcer to recur per chapter of the series after Bleublanc.
- Campanella's Japanese voice actress Kanae Itou also voices Jun Kohinata from Tokyo Xanadu, another video game of Falcom.