Anthony has never been a bad player, but I guess he could not fit into the Manchester United team or his price tag really affected his form. When he went to Betis he really played better and also improved the team and now that he has finally made the move permanent, I believe we will see a better Anthony and that will also improve Betis. Hopefully they can secure a Champions League spot, because they have started the league well.
Playing outside the Premier League is very different compared to other leagues. Most players find it difficult to perform in Premier League as the most difficult league i must say, even Raphina didn't perform as good when he was in PL playing for Leeds.
Premier League is no ground for average footballer, you need to be really good with toughness, while La Liga are where average players goes and they begin to perform much better. Real Betis signing Anthony was a good move, he fits their play and definitely will contribute a lot for them this season.