Kingsley Shacklebolt

Kingsley Shacklebolt was a Pure-blood wizard and an Auror. He joined the Order of the Phoenix after being convinced about Lord Voldemort's return. He worked undercover with the Ministry of Magic and misdirected the Ministry's efforts to locate Sirius Black. He fought in the Battle of the Department of Mysteries, and was later assigned to guard the Muggle prime minister, posing as his secretary.