I am about 70 gems short for a diamond box and I don't already have Herc

This is slow going for me! I'm using Holiday Mickey to try and get as many medallions as possible. If I can't buy a diamond box before Wednesday, I'll probably just give myself the goal of getting one Hades, rather than trying to finish the event. I shouldn't have spent gems on buying a Food Fight diamond box (didn't finish that event either).