Why him? Doesn't really fit a need and he wasn't very good at Bayern. Haven't watched much of him in Ligue 1 but I know Bayern couldn't wait to see his backside.
Just a really good player, can play almost anywhere in midfield, can dribble through the lines, any type of pass, powerful off and on the ball, and works really hard.
Big move early on and the Swansea loan didn't work for him, but has been really good at Lille and will certainly be moving upwards from there.