He is the cartoon villain of the piece, football’s black-clad master of the dark arts, the man who got David Beckham sent off in Saint-Etienne all those years ago. Beyond the caricature, though, Diego Simeone – the man whose Atletico Madrid side stand between Arsenal and the Champions League final on Tuesday – is a man who leaves a lasting mark on the players he works with. Just ask former Barnsley player Hugo Colace. Now a coach himself, the 42…