Signer
The Signers (シグナー Shigunā) are the only group that can summon the legendary Crimson Dragon, the embodiment of the red star. There are five people in the world that have the dragon birthmarks and five dragons that fit into the legend. So far only four of them are known: Yusei Fudo, Jack Atlas, Akiza, and Luna. The severed arm of the fifth signer is in Rex Goodwin's possession. However, in YuGiOh 5d episode 27, Luka (Luna's twin brother) apparently have the fifth dragon as shown in the Japan Version of Yugioh 5D's new ending animation, therefore Luka might be the fifth signer.
Each birthmark represents a part of the Crimson Dragon. Jack Atlas' represents the wings, Yusei Fudo's is the tail of the ancient dragon. Luna's and Akiza's birthmarks represent each one of the dragon's claw. A Signer's birthmark seems to glow when in proximity to a dueling Signer.
