Gekkou Kurenai

Kurenai Gekkou a freshman and also the student council president of Miyasaka High is a selfproclaimed genius. Nine years ago before the starting timeline of the story due to a certain deed committed by his younger twin brother Hinata Gekkou was prompted to constantly seek out power initially driven by the fear for his life and later motivated by the prospects of revenge. Gekkou is demonstrated to be quickwitted and highly intelligent. He wields an ancient fencinglike sword known as Spell Error and is trained in several traditional arts of exorcism. As the student council president he has made a contract with and is tasked to be guardian of the Holy Ground a location with certain special properties over which Miyasaka High was built. Source: Wikia