Aston Villa managed to make a surprise after successfully qualifying for the quarter-finals, but their chances of advancing to the semifinals are very small because they will face PSG who managed to eliminate Liverpool through a penalty shootout. Real Madrid once again showed its class as the most successful team in the UCL, surprises like this always happen in the UCL even though several teams have performed consistently in the domestic league.
Next, Madrid will face Arsenal, I don't think it will be too difficult for Madrid to eliminate them.
Although it will not be easy for Aston Villa to advance to the next round in the Champions League this season, I will not consider Aston Villa as a weak team and can be easily eliminated by PSG in the Champions League this season. Because other surprises can also happen to PSG when facing Aston Villa in the last eight, especially since Aston Villa themselves are also quite aware that PSG are tough opponents for them so Aston Villa will try their best when competing in the first leg in the last eight later.
Real Madrid are more serious in the Champions League than their own domestic league which gives them more motivation of winning the Champions League. Real Madrid and winning Champions League are more like siblings always finding a way to get attached, it's something they've been winning for years and still continue to bring such past and present glory to the club.
PSG has never won the Champions League which they strive for, their efforts might go for waste because the bigger pictures are crowned for the El Clasico. To all the effort they put, it's better trying than not atleast eliminating some potential threat was enough.
Arsenal also has never won the Champions League but I think they will not even near the Semi final due to injury crisis and their next encounter in the Champions League.