Dembele was good in avb's first season. There was a stat in the first 30 odd games that if he was on the pitch we'd never lose. Only when we bought paulinho next season, AVB tried to create a brazilian duo in midfield with Sandro (both portuguese speakers) and ruined himself.
Mason and Bentaleb were terrible players. We actually got less points in Poch's first season then in the clusterfuck Sherwood/AVB season. Only when poch realised his mistake the next season when Mason got injured that Dembele started getting games again and the rest is history.
Dembele used to drive everyone crazy in the stands. He would get the ball with a clear counterattacking opportunity and then spin on the ball and kill it and he would do it repeatedly. Whatever happened under Poch with his fitness or his use of the ball it transformed him. He always had a great skill set in certain areas but he went up 1-2 levels.