Attack On Titan: The Reiss Royal Family, Explained

Lurking in the shadows behind the de jure King of the Walls while masquerading as an ordinary noble family, the Reiss family are the true descendants of Karl Fritz — the 145th Fritz King who led the Subjects of Ymir to Paradis. With ancestry that traces back to Ymir Fritz herself — the mother of all Titans — the Reiss family are the latest branch of this once revered bloodline, the only ones capable of harnessing the full power of the Founding Titan. First introduced in the Uprising Arc of Attack on Titan, the family has contributed to a considerable number of major plot points in the narrative, most notably, in Eren’s inheritance of the Founder from his father Grisha.