User blog comment:Kuras/Fall Event 2016/@comment-26356092-20161205153341/@comment-26356092-20161206031635

Oh yeah, this might be a bit late, but for the E3 debuff, it might be:

E2:

1) 3 AS+ air raid encounters (without damage sustained)

2) S-ranks at all air battles (A, G, K, L)

E3:

S-rank C, D, H, J. Maybe A-rank K.

This might explain why I couldn't get the debuff when trying E3H. With 3 air bases of Reppuu and interceptors now, it is a cinch, but with only 2 air bases (4 interceptors, 4 Reppuu) back when I first unlocked E3, I kept getting AS. What annoys me is, I can't do anything about it; E2 is locked in Hard, and unless I can craft new interceptors (which currently isn't possible), I'm probably stuck with AS and can never debuff E3 no matter how much I try.

Hopefully, devs come up with a way for us to get more interceptors soon. My daily development quests need doing anyways :3