The S11 is an Elysian-made organic weapon, used exclusively by the Elysian military. The S11 has a very liquid body which can absorb a great deal of damage, and is the most common of the 'old school' Seraphs.

Seraphs are generally humanoid in appearance, with white rubbery, slimy skin. The flesh has a gooey, gel-like texture to it and is devoid of any hair. The head features two small black slit-like eyes and a large mouth full of sharp teeth. There is little, if any, features to distinguish one seraph from another. The seraphs are believed to breathe, feel, taste, and hear through their skin. Some seraphs will take on the form of others in order to deceive, but they are not capable of altering their own form without an original at hand to copy.

The primary ability of the S11 comes from its highly fluid body which gives it fairly staggering resistance to damage, combined with an enviable regeneration systems. All S11's have high strength, comparable to that of a NH-7 Nekovalkyrja, while others showed the ability cloak themselves within Star Army of Yamatai vessels and to shape their bodies into weapons such as hammers and swords. As noted above they are also capable of shape-shifting into any humanoid form of which they have an original to copy. In addition to this they secreted numerous toxins, capable of rendering a target unconcious - and designed to work against a Nekovalkyrja's immune system.

S11's tend to work well alone or in small teams, never operating in groups larger than three due to their lack of social skills. They are regarded as being utterly expendable by the Elysians, and are not thought to have a genuine soul. Though Seraphs have clearly shown signs of intelligence and sentience (although usually sadistic), as well as loyalty, no seraph has been known to show remorse.

At times Seraphs have formed the majority of Elysia's man-power, and while not as true at the moment they are still heavily used - although the relative exspence of the powerful S11 models means that preference has been given to the newer S19 model.