#1 A leader

Eric Cantona, Roy Keane, Gary Neville, Nemanja Vidic- some of the game's greatest characters have donned the red of Manchester United over the years and it goes without saying that sometimes you do need a ruthless force in your team who is hell-bent on winning games.
This is exactly what United lack at the moment and it is an attribute Alderweireld has. He is very vocal, is a proper commander from the back and is skilled enough to lead a team on his own.
He can be entrusted with leadership duties and his confident demeanour can be channelled to his teammates as well. Confidence and consistency are key to any title-winning team and in Alderweireld, United will get the perfect piece to complete their jigsaw.
Still only 29 years old, Alderweireld has a lot to offer and given the fact that United will be uncompromising in their quest to Premier League glory next season, the Belgian can make his mark at United, reduce the workload on de Gea and of course, propel them to the top of British football again.