Mine is probably Pyribbit from Super Kirby Clash and the Roaring Knight. Pyribbit spent literally the whole boss fight in the background making it impossible to defeat him in under 40 seconds which was a nightmare for missions. the boss fight wasnt actually a challenge at all. And the knight because even with the Shadow Mantle the knight is a freaking horrible thing that can one-shot the entire team with an incredibly hard to dodge attack at turn one. the worst thing is he sets defeated players's hp to -999 so there's no chance of you reviving them without specific items. but yeah thats my opinion.
thanks to img.flip for the pyribbit pic and tenor for the knight gif. no thanks to pyribbit and the knight >:(
