Garuel, formally known as Garuel, Seraphic Leo, serves as Mikado Shirogane's DigiFriend, a digital companion within the Shadowverse universe. He remains constantly near Mikado, often nestled in Mikado's arms, reflecting their profound closeness.

Garuel possesses a tender and kind nature. He shares an exceptionally deep bond with Mikado, having been Mikado's only companion for a significant time before the series begins. This connection makes Garuel Mikado's primary source of emotional support, especially evident when Mikado feels vulnerable. After Mikado's initial Shadowverse defeats, Garuel is always the first to show concern, actively working to help Mikado recover emotionally and move forward.

A pivotal moment occurs during a joint battle where Mikado and Ryoga face the opponent Himmel. Within this conflict, Garuel undergoes a legendary evolution, ascending to a higher state known as Garuel, Seraphic Shine. This form represents a significant power increase tied to crucial narrative combat.

Throughout his appearances, Garuel's core role centers on providing unwavering emotional support for Mikado. His actions consistently prioritize Mikado's well-being, particularly during hardship or failure, reinforcing the fundamental dynamic of their partnership.