Oscar Cole is an MI High spy and a student at St Hopes.
His mother, Jade Dixon Halliday, is a double agent, who's true loyalty lies with SKUL. His father, Edward Dixon Halliday, is thought of to be dead since going to Africa when Oscar was four. However, it is soon discovered that he is actually alive, after taking 9 years to escape from Africa.; he posed as Vincent to infiltrate SKUL and feed back information to M.I.9.
Oscar has poor interpersonal and social skills, having grown up losing everyone he loves. He is manipulative, sly, and clever enough to live up to MI9's expectations, if not exceeding them. He is adept at reading people, able to tell a villain from a hero in the people around him. Although he has immense emotional issues, he is selfless and heroic, always eager to save the day.
His skills are his extraordinary display of fighting skills and his mastery of deep cover. He is an excellent fighter, able to hold his own against several opponents simultaneously, and even bring down his own mother with little or no effort. He displays a more varied form of martial arts training than other characters in the series. In The Lost Hero, he uses superb martial arts techniques when fighting multiple opponents.