Seasonal buff preventing from achieving set mastery dungeon

Hello blizzard, is it possible to (temporarily) disable your seasonal event buff? The trials of the tempest buff is making my set dungeon mastery almost impossible. Im trying the unhallowed essence set dungeon. One of the objectives is to hit 20 enemies with 1 multishot. Im trying to mob the targets together, and then I start aoe-ing the mobs killing them… How am i suppose to get this mastery if the event buff is preventing me from getting the objective… Please let me know how to (temporarily) disable it.

This season - pure crap (cause sh*t is bad word). Nothing more to say…

You might try the marauder dungeon - I did that one - the buff actually helps a bit, and its probably easier than UE (at least for me). Also, you should be able to collect the items you need as you level (as you are p600+) already.