Subject-000 is a British superhuman with unknown properties in the care of The Chiasm Syndicate. They are blind, deaf, and partially numb, due to their powers. The Syndicate occasionally uses them for "containment of very dangerous things."
They are one of the 4 notable for being able to successfully combat 564, and are one of the most powerful people on Earth-Crimson. They are also notable for being incredibly dangerous, but not especially malevolent. In the case of an incident involving Subject-001, Subject-000 will be authorised to approach them. Hypothetically, this may extend to other dangerous Subjects.