From all aspects, these two teams have advantages compared to other teams. A number of great players belonging to these two teams will show each other their qualities to bring the clubs they defend to victory. Real Madrid and Manchester City have a big chance of winning the UCL trophy because their quality is above average. They are able to dominate their respective domestic leagues easily without any obstacles, especially Manchester City who managed to win the EPL trophy in four consecutive seasons. Every football fan really wants to see the two of them fight each other in the final to lift the trophy, a big match full of tension will occur because the two of them will buy and sell attacks to achieve victory.
Last season Man City failed to advance to the quarter-finals because they had to accept defeat when facing Real Madrid through a penalty shootout scheme. Next season will be a little different because there are several teams that have also made big changes even though in terms of quality and mentality Real Madrid is still quite favored. But for Man City I don't think they will reach the final because they didn't show their full strength like last season and there is a lot of competition that will later stop them like last season.
It is still too early to say which team is favored because the competition has not started yet, let alone the competition is still long. But if you calculate the strength of the team after the transfer market opens, Real Madrid still has a good chance of defending the title. Although it is not easy because there will be much tougher competition in the Champions League every season.