After Bellingham returned I thought this club would be strong again with a complete formation but instead Real Madrid had to take a big blow next knowing Mbappe was injured but fortunately his injury was not prolonged and was only absent for a few weeks after that Mbappe was able to return in a fitter condition after resting for 3 weeks.
Even though Mbappe is absent I don't think it has much effect on Real Madrid Ancelotti will change the formation as before when Mbappe was not there and Real Madrid will remain a club that is not easily defeated with the great players they have.
I don't think it will have any effect or.much effect either because Real Madrid have been good and playing well without him/befor3 his arrival to the club though with his presence it could be more better than it used to be , the club will find a replace for him though.The guy was just not lucky to arrive at the right time I think, I've always liked mbappe so much and seeing him going through this isn't really satisfying and I'm not also happy with it. First it was the club having injury players and now that the injury players are returning one by one, he ended up having injury.... I heard its going to be a three week out I hope he will be available for Barcelona vs Realmadrid at the end of October.
I think losing Mbappe will have a little effect on the performance of Madrid attacks even though as you said that before they also improved even though there was no French striker. Although it was seeded, but this season the strength of Atletico Madrid can also be said to be very good and is likely to be able to threaten Don Carlo's troops who came as guests at Wanda Metropolitan. I think the match will be very interesting and Atletico is very ambitious to defeat the city rivals and take advantage of their situation which cannot reduce full strength