>>33891578The extra difficulty modes in B2W2 clearly weren't playtested before release at all because the level scaling is totally fucked in Easy and Challenge modes. Easy is actually the hardest unless you grind due to less EXP between lower levels and EXP scaling mechanics, and Challenge is a joke from the extra EXP you get for the same reasons.
And that's why it hasn't returned, the workload for the balancing teams is tripled if they wanna do it right because they have to just as extensively test and tweak the non-standard difficulties as the standard one.