Those 2 aren't that bad, if you know the trick...
As for Lava Piranha, Use Sushie's U-Special. It practically CRIPPLES him, and the buds go down immediatly.
As for Huff 'N' Puff, use Lakilester's attack which damages all enemies. This is the easiest way to do it.
The "trick" I used for Kent C. Is to put him to sleep! He goes down for about 5 turns....
*My real signature went on strike, said something about "unfair working conditions". So, this is a temporary replacement sig, until I can work things out with the real sig.