Board Thread:Game Updates/@comment-3502824-20180207170103/@comment-3502824-20180216075702

Event Important News for Medium/Hard Mode Admirals
Starting from this Event, if you happen to be in Medium (乙) OR Hard (甲) Mode and have at the time depleted a high volume of the Boss' total HP Bar but decide to change down into an Easier Difficulty, your progress from the higher difficulty will be applied to the lower difficulty to a certain level. (More details to be known later).

Long story short: If you were attempting Hard mode but the Final Boss refuses to die so much during the Final Kill that you decide to go down into Easy mode, a certain level of progress you have made from Hard mode will be transferred into the Easier Difficulty.

(Though in what way, how much, and whether this includes Debuffs/Route Openings and etc. is unknown at this time)

https://twitter.com/KanColle_STAFF/status/964403186302779398 本イベより、「甲」作戦や「乙」作戦などの高い作戦難易度から、より簡単な作戦難易度に変更する場合、敵戦力ゲージを大きく削っていたケースなどではそれまでの作戦進捗の成果がある程度活かされる形に実装を更新予定です.