Cefiro commands the Seventh Legion in the Demon Lord's Army, holding significant authority as Ike's direct superior. She safeguards his concealed human identity from others. Her appearance includes blue hair, purple eyes, a witch hat, cape, opera gloves, and a dress.

Notably teasing, she employs provocative behavior toward Ike, using suggestive tactics like intentional nudity—emerging from a bath to unsettle him—to provoke reactions. Despite this playful demeanor, she exhibits genuine sisterly concern for his well-being.

Magically, she specializes in earth and darkness spells, conjuring restraining vines and teleporting between prepared locations. She favors flight magic for practical convenience over walking. Strategically, she participates in high-level planning, using chess matches as metaphors for military tactics.

Her experience includes capture and severe torture by the human Alliance of Kings during confinement. After rescue, this trauma drives more aggressive actions, culminating in her personally eliminating an antagonist involved in her suffering.

Within the military, she collaborates with alchemists to develop gunpowder for firearms integration. She manages internal threats, suppressing a subordinate's coup attempt against the Demon Lord. Her role evolves from mentorship to strategic partnership in campaigns pursuing human-demon coexistence.