Intro: I known this is funny, but i see many new commers confused about this event, lets me help NUTaku, make this event more clearly.
Guide for [Event] Bremen: The City of Ruin
This event is VERY VERY Simple, you dont need to do this or that for completed the event.
You JUST clear 4 maps then WAIT for NUTaku open next new 4 maps at April 26, 2016. Event ends and rewards at May 2, 2016.