Phoenix: Rettenjō

Phoenix: Rettenjō is a giant 55-inch nail. It possesses the power to destroy other  Nox weapons and sever ties with the Boundary. The core of Rettenjō is Kushinada's Lynchpin, which has the ability to stop the functionality of  seithr, resulting in the rendered uselessness of  Ars Armagus. Doing so, however, would cause the world's current  order to be destroyed; as seithr is something that is used in everyday life, the world would be without a reliable power source, and Ars Magus would cease to exist. Trinity Glassfield is the only person alive who knows its whereabouts, as it was believed to have been lost after the  Dark War, when in all actuality, it was in  Lord Tenjō's possession. Before Tenjō's untimely demise at the hands of  Jin Kisaragi, Tenjō gave Rettenjō to  Bang Shishigami, who is unaware of its power. In Bang's Arcade ending in  Chrono Phantasma, it is revealed by  Relius Clover that Phoenix: Rettenjō is actually an Anti-Nox Nyctores weapon built by  Konoe A. Mercury.