If we're just talking campaign, probably 7 since there's several fights approaching challenging instead of just one or two. If we're talking overall Gen 3 easily if with count the GC titles, but even without it Emerald's Battle Frontier has enough going on. Not all of it's good, Battle Palace is a war crime, but it is difficult.
As for the easiest, it's probably either 6 or 8. The only difficult thing in Gen 8 is the BDSP Battle Tower which isn't even that hard, but Gen 6 has basically zero challenge outside of maybe a particularly hard Super Secret Base team (which could theoretically exist but I'm not sure it could) and ORAS in general if you're extremely generous (and don't play like Yawnfag).
>>56558804At least they replaced the Champion with two fights, one of which actually approaches difficulty (shame about the legendary forced into your party for no good reason, but does fuck up Yawnfag's solo runs). Which is unfortunately more than I can say for XY, where the Champion's ace literally has an ability that does nothing so the Mega is just a stat boost. At least XY does have a fight after that, which is easy as shit, but that is in fact two mandatory post-E4 fights so I'll give it that.
