Ohhh, finally a character I have some first hand experience with, on the account that he's my secondary (points to sig).
Basically, Kirby doesn't play anything like he did in melee and he's been buffed in basically every way shape and form.
General (How Kirby Plays and general tips to counter his style)
Air
He, like a few other characters, is perfectly fit into the new physics system because his main combat zone is the air. I'll say it again, Kirby mains, myself included, love getting people in the air and chaining aerials together. Like Lucario, his aerials chain very nicely (all of them, uair >uair> fair>fair>bair and all the different possibilities in between using those 3 aerials) and he won't be afraid to WoP/FoP you. His multiple jumps allow him to stay on you and also allow him to place himself nicely for chains. In addition, he can also stall through air dodges and off the edges, so be careful. Just because you dodge a bair doesn't mean another one isn't coming in the exact same location. Now, he may have a very good aerial game but he does lack range that can rival with lucario (although his feet are disjointed hitboxes for some moves). Even in the air, if spaced and timed right, Lucario can come out ahead but, again, you have to be careful. Try to avoid juggling and keep the off stage chasing to a minimum.
Ground
On the ground, Kirby isn't as much of a pushover as some people might think and a few of his moves pack a nasty punch. Fsmash and hammer can both kill pretty early and fsmash is has quite nice range. In addition to this, almost all of the popular ground moves are set ups for aerial chases and combos. To list a few: utilt, dtilt, ftilt, uthrow, fthrow, dthrow, dash attack, usmash (at low %s). Almost every single move he has can be followed by something. His throws lead into combos at low %s. (Watch out for fthrow > uair > fsmash (aka the Gonzo Combo)) As well as dthrow > utilt > utilt .......
Again, use your range and keep him back. He's light and dies early but don't underestimate his killing potential. If he reserves his kill moves for killing, he can knock lucario out before his aura becomes a huge factor.
Gimping
Kirby is, more or less, a quite capable gimper. With the multiple jumps, the semi spike dair, the Wop/Fop and Kirbycide/Starshoot, he can pretty effectively stop quite a few character's recovery. Lucario's main flaw here is the startup time on his upB. A decent Kirby can most likely, chain a few bairs and get Lucario to a point where he won't be able to recover if the Lucario isn't smart with upB usage. You have to be careful and try to keep a sense of where Kirby is because if you don't, you shouldn't expect to recover.
Don't really try to chase Kirby out, ESPECIALLY if he's at high %s. It's overly easy to inhale a foolish edgegarder-to-be and just give up a stock to knock one off the opponent.
Important Kirby Strats/Moves
Throw Combos
Luckily for us, Lucario is floaty and isn't very susceptible to throw combos but they still pose somewhat of a threat especially against Kirby. If nothing else, his throws leave you in a position to be easily chased and followed by an aerial pursuit. I'll list the major throw combos:
Fthrow > uair > Fsmash/utilt - This one isn't as bad as what he can do to heavier characters but it still sets up for an aerial chase if he choses to do the utilt. It's only a threat when at very low %s but it will get you to about 35% right off the bat.
Dthrow > utilt > utilt > utilt . . . -This one can be avoided by Lucario (IIRC) by simply jumping and not trying to land. If you don't jump, you'll get juggled by a few utilts and then followed into the air.
Uthrow > fair - not much to it, just a small aerial chase could happen.
Other combos
dtilt > fsmash - dtilt trips, be careful.
Fast falled nair > Jabs - watch out for this, his Nair auto cancels and leads right into his jabs and it's an easy way to get a lot of damage if you aren't smart about it. Avoidable but be careful.
Stage
I'm not going to go into specifics because, to be honest, Kirby doesn't really have many stages, if any, that really destroy his game. At the same time, he doesn't have many that buff his game. As a general rule of thumb, I would avoid stages with platforms simply because it allows him to get under you and lead with an aerial. I suppose a flat stage where you can camp would be ok...at the same time he could always steal aura sphere and camp back in addition to just flying over the spheres.
Overall Match up
I would say 50:50 even.
Aerials
Kirby = Lucario
Ground
Lucario > Kirby
Camping potential
Kirby > Lucario (he can fly over and spam back equally as well, in addition he has his own projectile)
Recovery/Gimping
Kirby > Lucario
Killing power/survivability
Lucario > Kirby
Edit: One last thing I forgot regarding Kirby's aerial hammer.
Fear the second swing!!!!
