Talk:Halloween 2018 Event Revival (US)/@comment-43431208-20190920102202/@comment-2234004-20190920102634

To farm efficiently, you must wait for the highest difficulty to unlock, but you're free to farm now if you don't have anything better to do.

As for how to farm, borrow a servant with a MLB encounter up CE (encounter can't go higher then 100%, so 1 MLB is enough) and just equip as much of the currency CE as possible for the region.

Which CE to use in which area, you can see up in the quick farming guide

https://fategrandorder.fandom.com/wiki/Halloween_2018_Event_Revival_(US)#Quick%20Farming%20Guide