Leviathan is a tsundere and an otaku. He spends almost all of his free time watching anime, reading manga, or in some way consuming media. His laptop used for Student Council work has a giant picture of the character Seraphina plastered onto it. In the chat The Guest Room, it is revealed that Levi uses the guest room in Purgatory Hall as his own personal manga storage space.
He also spends much of his time playing video games, which he shows a talent for. He owns multiple gaming consoles.