Slicer Brothers  

Number 48

Two murderers with their spirits enclosed in one armor set, where one was placed inside the helmet and the other within the suit's body, served as guardians of the 5th laboratory under the name "Number 48." In an omake comic, the older brother enjoys cats while the younger prefers dogs. Their disagreements sometimes lead to arguments, but since the elder only has a head and no physical form, the younger always emerges victorious in their disputes.