Although ancient histories of 5,000 years ago tell of only five Signers, the show has officially hit a breakthrough, as a sixth Signer has miraculously appeared, bearing a sixth mark of the Crimson Dragon known as the heart, and wielding the last of the original five dragons that served alongside the Crimson Dragon, now finally revealed in Japan as Life Stream Dragon. Appropriately enough, when the marks become whole, the heart is shown to be held in the claw mark that Luna possesses. Now, both brother and sister are both finally Signers, meaning that their love and protection for each other grows even more unbreakable.
Leo's days of feeling like a burden and/or holding Yusei and Luna back are finally over, as now the Crimson Dragon has chosen him to bestow the power needed to protect Luna, a lifelong promise Leo intends to keep. Ironically, during the saga of the Dark Signers, Leo believed he was the fifth Signer because of his ace card, Power Tool Dragon. Well, he may not have had hidden powers to awaken back then, but he does now! The last of the five dragons from 5,000 years ago is now finally unveiled to us... and just in time for the believed-to-be series finale. How appropriate.