|Debut||BlazBlue: Calamity Trigger|
Phoenix: Rettenjō is a giant 55-inch nail. It possesses the power to destroy other Nox weapons and sever ties with the Boundary. This weapon was originally wielded by Bang Shishigami, it is now in Relius' possessions.
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.