Melody

Melody (めろでぃ Merodi) is one of the four Nexus Admins in Five.

Melody could be the "nickname" of his "surface" personality. For deeper reasons, Melody could've developed mutliple personality disorder. He could be like a dormant volcano, usually on his "Melody" personality, but under certain circumstances, his dormant personality manifests. This other personality could use different methods, including both executing his tasks as an admin, and fighting, using a different Deck and the such - making him a highly unpredictable opponent.

Melody
Melody's Deck is not named yet. It's a FIRE Psychic Deck featuring pyrokinetic monsters who live underground, closest to the Earth's boiling core.

His strategy functions similar to my d'Arc burn deck, using effects that heavily burn both players, but the owner's monsters convert their damage to LP, so the opponent's LP is depleted while the owner's just increases. The more the duel goes on, the wider the gap between the LPs becomes.

From primordial times, fire has been essential to humans' survival, keeping them warm, providing light, cooking their food, etc. Merodi's fiery monsters can produce light and warmth, but they can also become a devastating inferno. Metaphorically, this deck shows how fire can both mean destruction and life - bringing destruction to the opponent and life to the user.

Dormant personality
To be decided. Could be a theme involving lava or plasma in contrast to "Melody's" fire.