Name: John "Railgun" Iron
Age (15-19): 17
Unit class: Engineer
Weapons used: UMP. 2 Military grade 20 shot type .87 magnum handcannons, with interchangeable explosive, corroisve, regular rounds. Dual sided light weight titanium katana, with etchings of some unknown language across one side (sort of like Sting from the Hobbit). 6 home-made small explosives disguised as dice, each containing about enough explosive power to demolition one of the school building. Vial of liquid that instantly becomes a gas when exposed to air. When inhaled, it almost instantly detonates.
Club: Computing club, nanotech club, chemistry club, manga club

Background: John joined the school because of his high grades in chemistry, as well as his almost insatiable need to create deadly explosives/poisons and use them on others. Becoming a Butei just seemed like the best course of action for someone of his... assets. 

Other info: After a using a homebrew explosive, his gun became partially electrified for a short time. This propelled the bullets at extremely fast speed and power, which earned him a name with his crew - The Railgun