He's not going anywhere. By paying about 20m for him Dortmund showed that they have a big picture plan in mind to become a force in Europe again. And tbh, it is quite an interesting project. They've got a winning formula, a great coach, bright prospects and role players who get their jobs done and they're playing in the Bundesliga, a top-3 league in the world. Personally I don't see any of Dortmund's superstars moving in the next couple of years.