Arsenal really should be setting a final appearance as the required standard, now that they are on the easy half of the draw. Barca will be tough but Arsenal's superior defense is their biggest asset. And yes, I am writing off the other clubs. Atleti might just knock out Barca but if anything that makes Arsenal's life even easier in the semis.
Liverpool will have to overperform in a big, big way to reach the final or even the semis. It's possible in a knockout competition, but not likely. We should be able to beat Galatasaray. But PSG will probably knock us out unless something rather unexpected happens, and even if it does that's just an opportunity to get knocked out by even more irritating clubs in the semis.
I don't really care how it shakes out - my only hope, and it's a small one, is that the eventual winner is NOT Real or Man City.