my issue with him is at a stage normally where I would say like 2-3 years at a weaker top league club could benefit him than move to a top club but he actually had that period at Rennes and still is very raw. when to hold onto the ball, when to try his tricks, his whole off the ball game, stamina issues, bit strange given he spent 2.5 years in Ligue 1 already. would he be 2 years younger and got him straight from Anderlecht I would understand more his weaknesses.
City is a big and demanding jump for him.
anyway he has a lot to improve and I am sure he learnt a lot already since August, but long way to go if he wants to be a regular starter in this City team. for now I would send him on last 25 mins as fresh winger vs a tired defence. will watch him in Euros how he plays under different manager/system.