Phoenix Wing: 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 Tenjō Amanohokosaka's possession. Before Tenjō's untimely demise at the hands of Jin Kisaragi, he gave Rettenjō to Bang Shishigami, who was unaware of its power.

In Bang's Arcade ending in Chronophantasma, it is revealed by Relius Clover that Phoenix: Rettenjō is actually an Anti-Nox Nyctores weapon built by Konoe Mercury. Whilst what eventually happened to Bang has not been specified, according to Relius's Arcade ending in Chronophantasma, he succeeded in taking the Rettenjō from Bang.