What is your opinion about the PSG - Dortmund matchup? Honestly I believe PSG are here big thanks to their luck as well. That unbelievable red card Araujo got finished off Barcelona. This makes me question PSG's chance for even reaching the finale. Because their opponent in the semi finals is doing really good recently too. 
Dortmund eliminated Atletico Madrid which isn't really an easy job to do for even the biggest favourites of the title here. They did it in a really impressive way at the same time. I remember PSG - Dortmund games in the group stage but I still believe it might be different this time. Even if PSG advance I think it won't be easy.
I have the same thoughts as you, because we can compare between the first and second legs of the match between Barcelona vs PSG, we can see how Barcelona performed that was able to destroy PSG in Paris, as well as the second leg, didn't Barcelona play spectacularly and even able to score even before the game entered the 15th minute, I think Barcelona's performance in that match allowed them to win again against PSG but unfortunately As Gundogan said, Araujo destroyed Barcelona's dream of the Champions League with the red card he got in the game, PSG's success in advancing to the semi-finals certainly cannot be separated from their luck for Barcelona's misfortune which received a red card in the match, and maybe we would see Barcelona currently in the semi-finals if Barcelona did not get the red card.Dortmund eliminated Atletico Madrid which isn't really an easy job to do for even the biggest favourites of the title here. They did it in a really impressive way at the same time. I remember PSG - Dortmund games in the group stage but I still believe it might be different this time. Even if PSG advance I think it won't be easy.
The PSG and Dortmund match will be a rematch of the Champions League group F phase this season, Dortmund and PSG are in the same group and Dortmund managed to come out as group winners while PSG only as group runners-up, so I think both of them certainly have understood the character of each team's game, besides that PSG and Dortmund have met 6 matches and of these Borussia Dortmund twice won, PSG won one win, with 3 matches ending in draws, so in my opinion PSG should be careful with Dortmund because after all they are not an easy team to beat.