His ego is completely out of control and a salutary lesson to us all. When he moved to the UK he seemed a relatively diffident, shy, almost awkward young man. He didn't seem to bear any of the characteristics that often reveal themselves in male teenagers of contrary arrogance and willfulness. The Kevin and Perry effect.
Years of being feted by the media, club officials and supporters alike, as well as surrounding himself with people who spend all day telling him how wonderful he is, have turned him into a bit of a monster and a complete arsehole, it seems to me.
I don't doubt for a second the same fate could very well befall me if I lived through a similar period of unbridled praise and toadying. It's very hard for it not to affect any person to a meaningful extent. Anyone who thinks Messi hasn't developed a huge ego doesn't fully grasp human nature imo, although it doesn't manifest itself in anything even resembling such overtly obnoxious terms.
Being famous, certainly to that extent, is caustic for the soul; such as the human soul exists.
As to his footballing talent, he'd certainly get into my all time XI. Stronger, faster over longer distances and better in the air than Messi, but still not quite as good a player overall, but nonetheless an incredible footballer. Two of the very greatest players of all time have existed together in the same league for most of their respective careers, which has entertained us all. Both utterly sublime footballing talents. A joy to watch playing football to anyone who loves the game, surely.
I think he'll end up back at the rags in a couple of years when he's past his prime and on the decline, but still a hugely effective player. His ego will send him there because he knows he'll be more adored there, for going back, than going anywhere else.
He'll find retirement difficult, not least because I don't think he's got the intellectual capacity to fulfill an effective role in football as anything other than a figurehead, like Pele perhaps, who lives a life, I feel, that is a little demeaning given his exalted status as a player. Certainly top management is beyond him, I reckon.