Madrid is a club that every football player wanna association himself with in their career, they have made a standard for themself with any kind of European trophy you can think of in their massive numbers, and currently there are great super stars like Vini Jnr, Rodrygo, Carvajal, Valverde, Camavingha, J. Bellingham, etc, already in the club making waves in all competitors, so Mbappe coming in is just an inclusion of these beasts which I think he is not coming in as a messiah to the team but as a part to a whole.
It's important I remind us all that there was a time of the gallaticus but not much of a European title was attached to the squad, and just maybe, let it not be that Mbappe is arriving at a time when there could be a little pause in the streaks of champion's league trophy wins for real madrid.
Looking at the teams in the world right, I would say they have the biggest chance to win it compared to any other team which is why I would bet for them. It is not out yet, but when it's out, I am going to play to them on outrights to win the UCL at the start of the season, it is not guaranteed, but it's likely.
Mbappe and Real Madrid will clearly catapult them to the top of the list of candidates. This is not excessive because in fact Real Madrid was able to get the trophy before Mbappe arrived, so it really makes sense that many people assume that Mbappe will make Real Madrid even stronger next season. Real Madrid won the Champions League 3 times in a row from the 2015/16 season to the 2017/18 season and it is not an exaggeration if next season they are considered to have the opportunity to win trophies in a row with the resources they currently have.