Life Stream Dragon is a servant of the Crimson Dragon, commonly referred to as Signer Dragons. Leo is the Signer associated with this Dragon, although prior to this, he owned this card's mechanized form, known as "Power Tool Dragon". 5,000 years ago, Life Stream served the Crimson Dragon and fought alongside him and the Signer Dragons in the ancient battle against the Earthbound Immortals. However for an unknown reason, Life Stream Dragon was not present at the battle against Red Nova, and instead "Black-Winged Dragon" was.