Bahamut

Bahamut is a summon available to Johnny Madman in Ultimate Man.

Ultimate Man
After meeting The Fallen, Johnny recieves the "Dragon-Scale Charm" and is told by the Fallen that concentrating with all his heart on the charm would bring the Dragon King to this realm. During any battle, selecting the charm from the Item menu will summon Bahamut in a cutscene. Johnny is suprised at the dragon, falling backwards in fear. The dragon tells him that Johnny is now his master and will obey his command. Bahamut then appears in the Summon menu.

The Last Cycle of War
Bahamut is summoned by Johnny in his first battle. Bahamut tells Johnny to wait until Bahamut needs help and takes over the battle. This battle teachs the player the Assist System, and Bahamut is unlocked as the first Assist Character.

Combat
Bahamut is a "One-Time Summon," meaning that he only does one attack. His attack, Megaflare, deals massive non-elemental damage to all enemies.

Trivia

 * Bahamut's choosing of his master is reminisant of Ramuh in Final Fantasy IX.