By stamina and being energetic, Chelsea has the advantage, but by experience, Fluminense are ahead as they have more experienced players that have tasted different competitions and knows how to face challenges such as the one, they will be facing tonight. The match can swing either direction and will be no surprise to anyone who understand football. It's going to be a very interesting match tonight and the emotion of the supporters of both sides is already high.
I am not sure that Fluminense have more experienced players. I think they are equal in that regard but I still believe Chelsea are the stronger team at the moment. And if you look at the bookmakers odds it shows the same with Chelsea at 1.6 to win and Fluminense at 6. So I would expect to see Chelsea in the final although I doubt they can win this tournament because both PSG and Real look better right now.