Kirby usually ***** PT, unless he's retardly awesome and/or you're retardedly bad. Here's my advice:
Squirtle: He's the toughest of the bunch. He's fast and is difficult to gimp (due to his up-b). If he withdraws, use fsmash to push him backwards (and probably offstage). Try to get above him when he uses him up-b and bair or dair. If he's not in his up-b, try for a bair or a dair (still), but you can do it a bit more freely. Another method is to wait his stamina out until he has to switch to Ivy. There's no real fool-proof way to win this one. Maybe 50-50.
Ivy: You'll wanna take his power, then give him a bit of damage and knock him offstage. Even mediocre edguarding will kill him. 65-35.
Charizard: Also very easy. You're light and agile, he's big and slow. Focus mainly on your tilts here to maximize your speed advantage. The only thing you really need to watch out for is his rock smash, but nothing really bad right here. I'd say even easier than ivy. 75-35.
Overall, I'd say 65-35.
All the information is based on what I solely have seen, and that's, maybe, 30 brawls vs him. I don't have much experience, but the PT's I played were AWESOME.