The fact that Dortmund made it to the final shows that they can't be ignored here, they have been going against odds to get to the final but one thing is sure Real Madrid won't be sleeping especially from the fact that this is Toni Kroos last dance, they won't be sleeping and they are not the kind of team that slip off after winning a title, I believe that the defeat of Bayern Leverkusen will even make Ancelotti and his squad to be cautious of Dortmund.
I still feel Real Madrid will be victorious
Real Madrid can be considered superior, based on the last 5 head to head matches between Real Madrid vs Dortmund in the Champions League. However, we must know that Dortmund's last 5 matches recently, Dortmund is very favored with 2 wins in the Champions League and 2 wins in the Bundesliga, and only experienced one defeat in the Bundesliga match.
I think the Champions League Final this time will be very fierce for El-Real, considering that Dortmund's defense is difficult to penetrate and has conceded fewer goals than Real Madrid, and it is very likely that there will be extra rounds, or even a penalty shootout to win.