Paulinho was quite good for Barca in the one season he played there after going to China the first time, one of their best players in the double winning season. He also returned to the NT after being left out in 2015.You saw this a lot with China in the 2010s. The players who left for China and returned to Europe never accomplished anything, including the spaz Arnautovic. El Shaa is the only one I can think of who even returned to his NT.
It was always such an incredible waste he went to china in the first place though.
But money talks, especially for southamericans.