The Trial Series are artificial monsters created by BOARD, combining human and Undead DNA with machinery. They cannot be sealed with Proper Blanks; in fact, Blanks are absorbed, allowing them to recover quickly. The Trials were developed to interfere with the Undead Battle Fight. Unlike normal Undead, which are immortal, the Trials are able to be destroyed. In early production sketches, they were referred as "Undeadloids."