Wow, picked a bad time to be in meetings all day.
Last time I felt like this was 5-1 over Chelsea in 2000 after being down 3-1 after the 1st leg at Stamford Bridge. Unfortunately that season ended with an invitation to the Valencia rape party hosted by Kily Gonzalez, Claudio Lopez and Gaizka Mendieta.
Only got to see the last 30 minutes but two things stick out:
1) Neymar taking the FK and PK (very debatable, BTW) not Messi
2) Ter Stegen's tackle to win the ball late when a breakaway goal a la Fernando Torres in 2012 looked on
I really like the three-man backline of Mascherano, Pique and Um...titi which solves the problem of not having a RB. There's no depth there though so if one of them gets hurt, it's back to 4 in defense.