The Real Madrid team and especially Karim Benzema who scored three goals against Barcelona put on an amazing performance. Due to the fact that the most important rival of Real Madrid has been kicked out of the Copa del Rey, Real Madrid now has a greater chance of winning the trophy, and on the other hand, after losing three El Clasico games in the season, the team may be able to finally retaliate against Barcelona.
Benzema was making hatrick against barcelona. I remember when so many barcleona fans were mocking him if benzema was only able to do hatrick against small clubs. That has proven that benzema is real world class striker. 
If you have been watching full matches and you would able to see something interesting about gavi and how he has been triggered by real madrid's player. I would not be surprised to see that if gavi is very emotional.
The next match gonna be the easy team for real madrid. It seems like the chance for madrid to win the trophy is very high at this moment.
I consider about how good the performance of real madrid against barcelona after it was using 4-3-3.
yes, even though Barcelona is a team that is known for being strong and good, look at the reality Real Madrid gave Barcelona a big surprise. even though I didn't fully watch the match between these two teams, I saw replays from YouTube how embarrassed Barcelona were with a 0-4 defeat. very sad.
I think Robert Lewandowski should accept this revenge.