I'm interested in attempting runs again. I previously gave up because I kept dying to random stuff before even getting to chapter 7 and I remember using a different flaw in my ancient route I made back when I first played this game. Is there a different flaw that could maybe make the early game less of a reset fest or is Defense the only option for the Dark Flier route (I used Dark Knight back then because I didn't know about Galeforce yet)

Bane as Luck would be the next best option, however we want 38 magic at the end of the run and Luck as a bane would also decrease Magic growths by 5% (more specifically, Luck -10%, Strength -5% and Magic -5%) which now drops our average of magic from 39 to 37, lower then what the minimum we need for the boss. It is random level ups though, so it's possible you get 38, and worst case you can always second seal to level 1 again to spare your magic stat.