What more to expect from Arsenal than a comeback in the first half, in this second leg it will be tougher for PSG to score Arsenal, they had the first point too easily with a good goal from Dembele, Arsenal won't be keeping another opportunity for PSG to take advantage. 0-1 isn't a disadvantage neither can it be an advantage to PSG, on that day PSG won't be relaxing on that one goal, even if PSG beats Arsenal to qualify, it won't be on a 0-1 aggregate. Arsenal will first equalize then goals will be featured in that match.
Logically, Arsenal could not take advantage of good scoring opportunities in the first leg. While PSG competing away can put pressure on Arsenal and managed to win 1 aggregate score. Imagine how PSG will be stronger at home and surely Arsenal will also be a little disturbed by PSG fans trying to reduce the mentality of Arsenal players.
But we'll see what happens. Because I heard the news that Dembele is injured at the moment and could appear again on the 8th when the second leg starts. And if Dembele doesn't play in the second leg, things could get worse for PSG.