For completing this quest you need to finish all the EB goals and... You need to finish the Ashes to Ashes event, which is a box event. I have no clue what a box event has to do with being a master slayer, but the Master Slayer event ends 1 day 14 hours from now, while the box event ends 3 days 15 hours from now, so two days later. It would really be nice when the timer of the wrapper event would end on the same time the last event ends, especially when this is a box event...
