#The difficulty system first used in [[Spring 2015 Event]] returns: you can choose between Operation A ({{lang|ja|甲}}, Hard), Operation B ({{lang|ja|乙}}, Medium) or Operation C ({{lang|ja|丙}}, Easy).
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#*Choosing A or B requires certain HQ Level (HQ Lv 35 for B / 80 for A in Spring 2015 Event).
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#*'''An important note''' to all Admirals intending to clear the event on Hard difficulty - further (new) conditions now apply:'''
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#**When switching difficulty from ''any other difficulty'' to Hard, the map's debuff mechanism (where applicable) will be reset.
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#***Switching between any other difficulties will not reset the debuff mechanism.
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#The debuff system of [[Summer 2015 Event]]'s final map, where certain nodes had to be killed to reduce boss armor, returns.