Кумаґава Місоґі

As a negative person by nature, who could kill a person just as easily as he could breathe, Kumagawa thinks nothing of the lives of the people around him and could easily take them away. Despite the immensely negative personality he possesses, he has a purely positive outlook regarding himself and is always seen smiling. As a child, he was tested for abnormalities, but was believed to be normal.

His minus, "All Fiction", allows him to erase the existence of things; this includes things with or without form, injuries, his own "aura" and other minuses, as shown when he tried to make Emukae's minus become nothing.

Chapter 71 was the first time he expressed a emotion, which was anger (Most of the minus are usually emotionless). As stated by Medaka, he actually does care for his comrades. Later he traded "All Fiction" for his original minus, "Book Maker", which allows him to turn the target into a minus. This was proven in his battle against Medaka. After he admitted his own defeat, Kumagawa was given the Student Council Vice-president position by Medaka, which in turn, made him the final member of the Student Council.

Ten years later, Kumagawa's whereabouts are unknown. His message to Medaka from the 100 Flowers Run is revealed to be that he had fun the past four years.

(Source: Medaka Box Wiki)