The reviews I've read are that he's very raw, but has the potential to be a superb player. I think Everton's interest is a short term thing, bring him in build up his strength and develop him then sell him on to a big European club for three or four times what we paid for him once he scores a few in the PL. From reading up on him it seems he wouldn't be good enough now to get gametime at a Barca, Milan, United, PSG level club but that they think he'll end up there. AC Milan have been linked to him for a good 12 months now and Arsenal had a bid turned down recently for him. His club have since been relegated and would now accept less than £5m, provided most of it was up front.
Sad to see but ultimately it probably isn't considering what the alternatives could have been. He seems to have the PMA to turn it into an opportunity rather than being dragged down by this news.
