|Voice (Japanese)||Yuka Iguchi|
Mugen (ムゲン) is a character in the anime and manga series Saikyo Ginga Ultimate Zero Battle Spirits.
Mugen is a small red dragon. He has white on his stomach, the back of his tail, and the tips of his hands and head.
While Mugen is good friends with Rei, he seems to like to argue with him as well. He's a fan of Magical Star. Mugen is known to fart at people, normally the Triumvirate, to send them away.
Mugen is Rei's partner. He is actually a card, Mugendra. He doesn't seem to like Ian, though they can get along.
He met Rei sometime after he acquired Ultimate-Siegfried and Ultmate-Odin, and thus doesn't know about Rei's past.
Mugen's love for Magical Star led him to purchasing a very expensive figure of her. He spent all of the crew's money, so they decided to look for work to earn more. They ended up becoming bodyguards for Magical Star's first ribbon, which was actually stolen by the person who currently had it. After getting the ribbon back, Mugen found out that Magical Star would actually be on the planet where they were.
Mugen planned to return the ribbon to Magical Star, but ran into Watari, literally. The bag carrying the ribbon was damaged, which got him mad. After learning that Watari and the rest of the Triumvirate had kidnapped Magical Star, Mugen was furious, and wanted to battle. He couldn't, so Rei battled in his place, and won. However, he sacrificed Mugendragon to summon Ultimate-Kingtaurus, so Mugen couldn't even give the finishing blow. However, he was able to return the ribbon in the end, which made Magical happy.
When Rei recieved Ultimate-Siegwurm-Nova, it seemed to have a strange effect on Mugen. However, he was cured of it once Rei summoned him in a battle.
- He is the first spirit to be treated as an actual character.
- He was shown to also be able to play Battle Spirits, despite being a spirit himself.
- He appears on the promo cards The Strongest Galaxy Ultimate Zero, Let's Cooking! and Mugen Flame.