you only have 1 minute and 20 second (80 second total) thank you for the cutscene that eat your 5 second tho.
remember when i said save your MP potion? i'm not kidding. the moment you escape the final boss room you need to fly up high, high jump won't be enough, you need to do the air screw while holding up to make you fly up. take left path after you fly from save point before boss room. watch out when you go left, there's flying enemy from below the ground that will stunt you.
the left room is a long corridor with huge enemy on the ground and flying enemy, put some shield and fly with air screw to reach the other side. while you flying make sure to spam some MP potion when you fly cause you will out of MP fast here. keep going until you reach intersection of up or left, left is previous boss room but don't take that path, go up instead. keep doing the air screw cause you move faster with those. ignore literally every single enemy you encounter, your time is short. if you feel lose open the map and calm yourself, the timer stop when you do so, formulte your escape plan properly
in short, thing that you need to know for escape: spam air screw, have like at least 15 MP potion to make sure you won't out of it