Obviously, no one has ever made a previous prediction that Dortmund will reach the UCL final based on its performance in the Bundesliga, which is still having difficulty competing for the title. You could say this season is a very good season for Dortmund. They didn't spend too much money in the transfer market to bring in players, only outcast players from other clubs were brought in and then managed to be polished into important players in their squad. Dortmund opportunity to win the Champions League is wide open, they have the quality to win this most prestigious competition.
Real Madrid is indeed a tough team, but they can still be beaten if Dortmund manages to take advantage of every opportunity they have in front of their opponent's goal. I hope the referee is able to maintain his neutrality in this game, so that incidents that are detrimental to Bayern Munich do not happen again when the referee excludes Var when disallowing De Ligt goal which is considered offside.
In fact, Dortmund was not part of the favorites to hold the UCL title during the group stage at that time and people or even bookmakers only favored big teams that had higher quality players but with the advantage of Dortmund being able to improve the performance of its players, it could produce good results. It's very good this season to be able to reach the final round even though you will face the most difficult team.
there are no players who look shining in Dortmund line up and as you said, some players are just free players or on loan from other teams, like Sancho, even though he is only on loan, but in fact, with Dortmund advantages, they can build Sancho into a more talented player.
Dortmund chances will be very big in the UCL as long as they don't ignore every single gap that Madrid is always targeting.
If we understand that Dortmund can actually get an even bigger opportunity if they are able to come up with a strategy of playing the ball up top which will make things difficult for the Madrid players because physically Dortmund are far superior.
and if Dortmund wants to win the UCL title they shouldn't let Vinic and Rodrygo have free space in every minute.