“They’re gonna have to kill me to get me off here!” a shirtless Harry Styles screamed as he rounded off the last date of his North American tour in New Jersey. The audience – made up of girls, women and chaperones of varying ages – roared back agreeably, bringing the atmosphere of the room from feverish to feral. Such is the white-knuckle grip of the former One Directioner-cum-megastar on the modern world today. You see, Harry Styles has what most people would call the It Factor, an undefinable synchronisation of charisma and likeability most would kill for but few have.…