Talk:Fall 2016 Event/@comment-26717891-20161121131005/@comment-27279544-20161121133423

Apparently it's still under investigation but here what the wikia say:

[WIKIA CIT.]
 * NOTE: The certain requirements is still under investigation. Do note that something might be missing.
 * S-rank node C,D,H,J and K in E-3
 * Slow-fleet CTF is suggested to reach D,H and J
 * Fast-fleet STF is suggested to reach C and K
 * Take no damage from air raids in E-2 twice in a sortie, two times (so 4 times in total)
 * (??)Perfect S-Rank all air battle nodes in E-2 Note
 * Note:. People have had the unlock debuff sound occur for them ending on nodes C and D in E-3 as well as after getting two runs on E-2 without sustaining any air raid damage (which is what I got), so at the   very  least those things are necessary.