Innocentius represents K.P.A. Italia and commands K.P.A. Scuola as its Pope-President, the setting's premier academic institution. This role grants him significant global influence. Driven by ambition to expand his power and authority, he justifies his actions through the pretext of faithfully recreating historical events. He possesses the Mortal Sin Armament Stithos Porneia, embodying Lust. This weapon nullifies the effects of enemy active abilities and prohibits all ability activation within its operational range during combat.

His strategic interest in powerful artifacts led him to travel to Mikawa with Galileo to observe Lord Motonobu Matsudaira's unveiling of Mortal Sin Armaments. In debates and political maneuvering, his cunning finds notable match only in Toori Aoi—whose unconventional tactics, like dirty jokes, disrupted his composure—and Masazumi Honda, leveraging her family's political background. His character design and role draw inspiration from the historical Pope Innocent X, Pontiff from 1644 to 1655.

Tadatsugu Sakai, who knew him in their youth, distrusts him, sensing danger in his intentions and motivations.