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I play Hackmons cup a lot. I think it should have a sleep clause just like random battle. I know it is obviously a format with not many rules, but I think would be a good one.
It's based off of Classic Hackmons, which has basically no rules, so I don't see why there should be a sleep clause when there's a lot more broken stuff available, coupled with the low chance of even getting a sleep move in the first place.
apart from levels, hackmons cup is completely random. adding clauses to a meta that isn't balanced or intended to be doesn't make much sense. random battle contains viable sets and does try to be balanced.