In The Legend of Zelda: Spirit Tracks, Malladus is the demon king. Long before the game's events, the Lokomos fought Malladus and sealed him beneath the Tower of Spirits using the Spirit Tracks, magical chains spread across New Hyrule.
The seal weakens when the Spirit Tracks begin disappearing. Chancellor Cole, secretly Malladus's servant, removes Princess Zelda's spirit from her body so Malladus can use her as a vessel. Link and Zelda must restore the tracks, repair the Tower of Spirits, and prevent the demon king from returning to power. Malladus eventually possesses Cole after being forced out of Zelda's body.
The final battle requires Link and Zelda to combine the Bow of Light with the Lokomo Sword. Bellum is the major antagonist of Phantom Hourglass, while Vaati belongs to games such as The Minish Cap and Four Swords. Ganon is the famous recurring villain of the wider Zelda series, but Spirit Tracks specifically identifies Malladus as its demon king.