If he chooses the right club and coach I think he could be a very shrewd signing for his new team. I get that there are concerns over his attitude and injury record, but at least the former can potentially be managed and who's to say he hasn't matured? He's about to turn 25, so all the reported attitude problems happened at a very young age, not that unusual for a young person even if the modern football world demands extreme professionalism from early on.
Could see him going to Chelsea if they try to get rid of some of their attacking players, given he's played under Tuchel in his one season with Dortmund. Don't remember if they had a good relationship but he performed well under him, and Tuchel was let go before Dembele started acting up to force his move to Barcelona.