Luneth is the main protagonist in the 3D remake of Final Fantasy III, and the first character to become available. He is one of the Warriors of Light.
In Dissidia, he's only known as the Onion Knight, a recurring character in the Final Fantasy series. He first appeared in Dissidia Final Fantasy as a representative of Final Fantasy III, based on the Onion Knights of the original NES release of the game. Since then he has made many other appearances in spin-off titles as a representative of Final Fantasy III.
Body of Dark, Heart of Light[]
He hasn't done much, excepting he was one of the Cosmos Warriors that Cecil first met. But he was questionable of wielding both light and darkness and thought he can wield both without issue since it's just like any other skill/weapon, but Luneth just gave him false advice on not ever using his umbrakinesis as it'd consume him.
Dissidia Shadowgate[]
With Firion and the other Cosmos Warriors, excepting the Warrior, Luneth wound up at the woods before Stormhaven the reunited with the fallen allies on their mission to prevent the warlock lord from awakening the Behemoth. Throughout Shadowgate, he became a sort of bookworm, as he learned all kinds of spells such as Epor, Terrak, Humana, and so on. He even retrieved and tested various items like the Silver Horn or Flute, though he was terrible in battles such as being too weak against the dragon or the Hellhound. Even being a little dastardly while opening random caskets. Although, he was devoted as he had a duty to uphold and save various homelands including Ur from the Behemoth's destruction. Thanks to Firion finishing the job, he was soon able to return to the orphanage and reunite with Arc, Toppapa, and Nina.