Sabot/14/Mage
The student at Coepit who calls himself Sabot has expressly stated that his goal in life is to be "as evil as possible"[sic]. He practices his evil laugh in the mirror and makes frequent use of "dark magic", which is simply standard magic with an added illusion to make it look black. Sabot isn't his real name, obviously, but he refuses to tell anybody what it is. This has led many to theorize that it's something incredibly mundane, like Josh.