Developed from the GN-004 Gundam Nadleeh, the GN-009 Seraphim Gundam is usually hidden on the GN-008 Seravee Gundam as a backpack unit. Seraphim detaches from Seravee's back and changes from its Backpack Form to its MS Form only when necessary, and this can be done even when battling. Like Nadleeh, Seraphim is equipped with the "Trial System" as its main feature. This system deploys an invisible field around the mobile suit, enabling Seraphim's pilot Tieria Erde to take control of machines within the field that are linked with the quantum processing system Veda.
Seraphim's Trial System is an improved version of Nadleeh's and has a much wider range. However, the system still requires its user to be linked with Veda. Tieria, who lost his link with Veda in AD 2308, was hence unable to use the system until his link was restored in AD 2312. A huge Gundam face hidden on Seraphim's chest is exposed when the Trial System is activated, and this is the same huge face that appears when Seravee is in "Face Burst Mode". Unlike Nadleeh which was intended to be used only in an emergency, Seraphim was developed with regular combat in mind.