Flame is very energetic and is eager to use his fire abilities. Shirobon's Flame Bombs do not harm him at all and actually encourages Flame to want to use his abilities. The symbol of Flame's back will manifest into a real dragon that holds his bomb in its mouth. It covers his arm and he uses it like a cannon to fire his bombs.
Shirobon's Fire Bomb gave him more power but he was unable to withstand Shirobon's stronger Fire Bomb. Thus, he became the first member of the Shitennou to be defeated.[Source: Bomberman Wiki]