This will be a big derby match. Borussia Dortmund managed to win the match last week by scoring 3 goals in 30 minutes. They were shown a red card and finished the match incomplete, but they were still good. Of course, the opponent in that match was Wolfsburg. The match we are talking about will be against Bayer Leverkusen. We know how quality a squad Bayer has. If Borussia Dortmund wins against Leverkusen, they can enter a recovery process. However, if they lose against Leverkusen, then we can say that it will be the beginning of a difficult time for the coach.
Both Dortmund and Leverkusen are strong teams with their own strengths. Not many teams are able to beat Dortmund at Signal Iduna Park, their strength seems to increase in front of their own supporters besides Nuri Sahin's reputation is at stake in this match because as you said winning a match as important as this will increase Dortmund's motivation to rise.
On the one hand Leverkusen is also aiming for victory, of course the main reason is to continue to approach Bayern Munich.
Who will win? Obviously, those who play effectively.
I don't find Borussia Dortmund that effective lately.. Bayer Leverkusen dropped also comparing to the previous season but they are doing fine right now with successive victories in row.
The advantage of Dortmund is the fact that they are playing home, otherwise Bayer Leverkusen is better and will win in my opinion. If Borussia Dortmund played well, they might manage to get a draw thought.