Problem with Fazio is that he's thick as a brick. He has great physicality, and will do his share of last-ditch blockings and recoveries that will make him look good, but he's prone to clangers, terrible decision-making and Titus Bramblesque acts of WTF defending.
It's the kind of guy that you look at him and think "when he sorts out his mental game, he'll be great". But Sevilla have been waiting for that for 8 years, and eventually have given up.