I've historically been on the Celtic side, as their politics are closer to my own, and there are lots of connections to Liverpool for the same reason (both sing You'll Never Walk Alone, though Dortmund does as well - when LFC played Dortmund in the Europa League a few hours ago, it was incredible hearing both sets of supporters sing it together). When Gerrard went to Rangers, it wasn't a happy day for me. Also, Dortmund has among the best supporters in Europe, and Klopp still has strong connections to the club.
BUT, that said, the best thing about the knock-outs is a good old-fashioned underdog story, and this definitely qualifies. It'd be a great story for Scottish football. I turned it on when I saw the score was 4-1, and while Dortmund did pull one back with a speculative long shot, Rangers had more chances and control of the ball right up until the last few minutes of stoppage time when they starting sitting back.
Barcelona and Napoli drew 1-1, which was apparently a fun game. I'd love to see Napoli dump Barcelona from Europe altogether. And Lazio lost 2-1 to Porto, which is always fun as a Roma fan. I like Sarri (and wish Roma finished the promised deal with him instead of being tempted by Mourinho's resume), but not enough to want anything but losses for Lazio...