Oh and by the way.
He wants a game that is permanately free. I suggest Mabinogi. It may be from Nexon, but as I said it is the best F2P MMORPG I have played.
So long as it doesn't rely on purchased items.
I'm going to say Perfect World, because any class can be played without needing a certain build, other than the fact that melee classes and archer don't need magic. You can easily live without the cash shop items, and if you really needed something, there's a gold(cash currency) trading system ingame, where you can buy and sell gold using coins(normal ingame currency).
But when I play MMORPGs, that's not what I look for. MMORPGs are boring for me if I just kill stuff and spend points, so I play them for player interaction.