the difficulty of the challengers isn't really the big issue - what is super-annoying about them is their massive abuse of OPB abilities (getting pillows thrown at me up to 10 times plus being frozen in a single fight is just awful and makes those fights more of a "how often can they use their OPB abilities this time?" luck-streak than anything else )
anyway, let's see whether there'll be a next wave, still able to kill them all on mighty