But a nightmare could come and destroy the hopes of everyone who wants to see Liverpool compete in the Final against Leverkusen. The nightmare is that Liverpool and Leverkusen could meet in the semi-finals and not in the final. 
Or it could be that one of them unexpectedly falls first. because there are teams from Italy that dominate the teams that have qualified for the quarter-finals this season in the European League. And usually teams from Italy are always good at making surprises in a competition. Due to the fact that in several seasons I have seen the top teams lose early in the European League and in the end the Final only features teams that were initially not seeded at all.
Just like in the champions league where Manchester city and Real Madrid has been both fixed to play against each other in a game meanwhile we were all expecting that they would be meeting in the finals but it's funny how they happen to be meeting at the quarter finals not even the semifinals thereby stopping one of the teams from getting to the finals a.d like you have stated, such could be possible in the Europa too.Or it could be that one of them unexpectedly falls first. because there are teams from Italy that dominate the teams that have qualified for the quarter-finals this season in the European League. And usually teams from Italy are always good at making surprises in a competition. Due to the fact that in several seasons I have seen the top teams lose early in the European League and in the end the Final only features teams that were initially not seeded at all.
I understand it's very possible that Liverpool and Leverkusen may not get to meet in the finals but then I don't think the council in charge of Europa would want that to happen because they know how well the anticipation on Liverpool and Leverkusen meeting in the finals has been on most persons an how much view such finals nis definitely going to get and that alone will keep attention to the Europa till the end of the Europa, except either of these team naturally happens to exit before the finals I think it will be best to allow them meet in the finals and the best teams should win.
I'm aware the Italians would want to try their best such as AC Milan would ant to contend so hard but this season isn't looking like one of such season where they can actually just come and hope to achieve such as the pressure and competition that will be seen in this season will actually be quiet different from that which has been seen in previous Europa where the Italians were able to show their prowess.