|Once...we were Marley, a nation of heroes who had defeated the Eldian devils. But now...look at what we've become...|
|— Calvi laments the decline of his nation's power|
Calvi was a lean man in his late middle age. Being an officer holding high status, he was always seen well groomed and wearing a unique uniform which featured a sash running diagonally from his right shoulder to his left waist, on top of the standard Marleyan tunic and shirt. He also wore four medals on his left chest, presumably indicating his position in the military hierarchy or past battle honors.
As an important leader of Marley's military force, Calvi was an authoritative figure to his subordinate officers, being able to demand answers from even Theo Magath, commander of the Eldian unit of the Marley army. Being Marleyan by heritage, he was proud of his country's glorious history against the Eldian Empire, but he had also shown distress towards Marley's weakening status in the modern age. He shared his subordinates' contempt of Eldians, although it was expressed with more subtlety. For example, when he approved Zeke Yeager's proposal to seize the Founding Titan again, he sarcastically remarked that his loyalty was not doubted because of the latter's betrayal of his parents in the Eldia Restorationists.
At the conclusion of the Marley Mid-East War, he presides over a meeting attended by Warchief Zeke Yeager, Commander Theo Magath, and other high-ranking officers of the Marley military. Citing the world's response to the recent developments of anti-Titan artillery, he becomes frustrated at how the world opinions favored the losing Mid-East Allied Forces, dimming the victory. He seeks opinions from Magath, who explains that Marley made a mistake for relying too much on the power of the Titans while neglecting the development of conventional weapons. As the result, the military technology of Marley is now being left behind from the rest of the world. General Calvi reluctantly agrees, lamenting how his great nation, which had defeated the Eldian devils in the past, has been reduced to such dismal state.
Zeke, upon obtaining his permission to speak, proposes that another attempt should be made to seize the Founding Titan from the Eldians on Paradis Island. Calvi asks him whether his proposition stems from a desire for revenge against his failure four years ago. When Zeke replies affirmatively, he seconds his advice by promising that it would be forwarded to the upper hierarchy.
One month later, Calvi attends the Tybur family's festival in the Liberio internment zone along with a number of high-ranking military officers. He briefly discusses with a subordinate about the security of the event, which is handled by Magath. When Willy Tybur reveals the truth about the ancient King Karl Fritz, Calvi contemplates in the midst of hotly arguing officers. Willy's speech continues, culminating with a declaration of war against Paradis Island. At this time, the Attack Titan transforms, bursting through the stage and slaying Lord Tybur. It then turns to Marley's military leaders, and Calvi can only solemnly stare as the Titan lunges into the crowd, crushing the officers.
- Calvi bore a strong resemblance to the real-life Danish actor Mads Mikkelsen.