Talk:Summer 2016 Event/@comment-25274414-20160815011658/@comment-26351458-20160815013756

From what I've read, the "quest complete" sound plays when you RTB after fulfilling the debuff requirements.

I took this link from the a few posts down, and it's for E-3 but it probably works the same way as E-4: http://www.nicovideo.jp/watch/sm29448789