Sure, you know the first leg is always more important than the second leg and now that barcelona have succeeded in wining them with 4 goals. The possibility for them to win back with this goal margin is something anyone can not think nor imagine that it will happen due to how consistant barcelona is towards chasing this champions league title, so I don't think if there's still a hope for dortmund.
For my ends. There is not even hope for Dortmund in winning against Barcelona in the second leg; that is what won’t happen. Barcelona are in their best performance this season, and currently, with the way Barcelona's performance is going, Dortmund can not score as many goals as Barcelona did in the second leg.
I’m even thinking that Barcelona will score more goals in the second leg. I’m not underrating Dortmund for saying this, but this is just the fact; they can’t beat Barcelona in the second leg. In fact, Barcelona will not even happen.
At this time it is certain that 99% of Barcelona's chances are already in the semifinals, in the second leg it will still belong to Barcelona. Moreover, Barcelona's game this season carries the philosophy of ball possession combined with direct play, plus high pressing, their defense is also disciplined especially in setting offside traps. Even if Dortmund wants to return the aggregate, of course Dortmund must play aggressively which means their game will be more open. Not underestimating Dortmund but you know Barcelona when their opponent plays openly. So it seems Dortmund will think twice if they want to play aggressively.
Interestingly, Barcelona under Hansi Flick has succeeded in creating a trio like the Messi, Neymar and Suarez era again, namely the Lamine Yamal, Rafinha and Lewandowski trio which makes Barcelona's attack line very adept at breaking down the opponent's defense. After seeing the game of Real Madrid and Barcelona in the first leg of the Champions League, I am sure Barcelona can win the La Liga and Copa del Rey trophies this season and it is even possible that the Champions League will be too.