A Rare Kind (珍種, Chin Shu) is a person with the ability to negate the Special Powers of others. They are unlike other power users, in that their lost form requires an elixir to restore their original form. Their blood is also needed to open Pandora's Box.
According to Yukihina, Rare Kinds have no reason for killing; they just are so innocent, they do not understand the meaning of life, and so they kill without second thought. However, "Fussy Lunch" wishes to kill all humans because humans themselves do not understand the value of life.
Known Rare Kind
Powers
Divine Shield: Rare Kinds have the ability to negate the special powers of others. It seems that this power is in their blood, as Shibuya's costume is coated with his blood and special powers cannot affect the costume. Another example is that the new school building was built with Shibuya's blood mixed in, making it so that special powers couldn't be used in the school.
Death God: Rare Kinds also have the ability to use their power offensively, by draining vitality, which is the orgin of special powers. If a power user is exposed to this long enough they will turn to their lost form, and continued exposure leads to death.
Enhanced Speed and Strength: Rare Kinds possess a natural increase in their overall strength allowing them to pick up objects much heavier than them and move at a rate faster than normal people can do. Their speed and strength are so enhanced, they can easily fight with Power Users without getting hurt.
Weaknesses
Shrinking
It seems that when a Rare Kind over-uses their power, they shrink into a miniature version of themselves. Unlike the Power Users' lost states, they will not return to normal after twenty-four hours. A special elixir made with the blood of a Rare Kind is required for them to return to normal.
Vital Spot
Each Rare Kind has their own vital spot, which once touched, will render the Rare Kind into a drunk-like state.