In the Anime
The Corpse Corps were created by Van Argiano, using the research materials of Collins and Julia that perfected Dr. Boris' previous attempts in Khilbet. They are kept under the command of James. Initially, the Corpse Corps are used as a tool by Amshel to serve as a replacement for national militaries when Van is sent to sell the Corpse Corps' services to their governments under the guise of protecting their people from chiropteran attacks, which were staged by Cinq Flèches using Diva's song. The Corpse Corps manage to kill most of the surviving members of the Schiff, but with help from Saya they are able to eliminate the Corpse Corps.
They closely resemble the Schiff (especially Moses in terms of physical structure) in abilities, being the ultimate form created from the same base, with the exception of not developing the Thorn. They are skilled fighters void of emotion and are able to transform their left hands into longswords to use in combat. Their strength and speed are higher than that of the Schiff. Their initial life span is 7 days, which, if necessary, can be extended manipulating the blood. However, they are equally vulnerable to Saya's blood.
In the Manga
In the Blood+ manga, the Corpse Corps are created by Van under Amshel's orders.
They resemble Charles because they are actually his clones. Charles is picked to be their base as he was Diva's favorite chevalier (in the manga only). They have the unique ability to stop regeneration of chiropteran hierarchy (queens and chevaliers). The only dangerous part of their limb are the claws which display their unique ability.