Poor Lucario.
Lucario is still a pretty good Pokemon, but it suffers from a huge case of a stat being not enough. While base 110 attack and 115 special attack are high, neither are very high. Base 90 speed? In this metagame, 90 is not fast enough anymore. These stats that are not enough do come with boosting moves. When it comes to stat boosting, Lucario truly shines.
Lucario has access to Swords Dance, Nasty Plot, Agility, and Work Up. This makes for great potential in physical, special, and mixed attacking. While tricky, Lucario could also pull off a double boosting set.
When it comes to attacking choices, Lucario is not lacking. STAB Close Combat, STAB Hi Jump Kick, STAB Aura Sphere, STAB Vacuum Wave, Dark Pulse/Shadow Ball, Crunch, Ice Punch, Stone Edge, Extremespeed, Psychic, and Dragon Pulse pretty much makes up Lucario's usable movepool, and that is a lot.
I already mentioned some problems Lucario faces, but here are some more. Lucario now has to compete with more fighting types like Conkeldurr, Mienshao, Cobalion, Terrakion, and Virizion while having to outshine old fighting types like Machamp, Breloom, Heracross, Infernape, and Toxicroak.
Lucario is still a good Pokemon. Just remember that it will never live up to its old hype.
Aura Sword!
Nature: Jolly
Ability: Steadfast (always)
EVs: 252 attack and speed, 4 hp
@: Life Orb
Swords Dance
Close Combat/Hi Jump Kick
Crunch
Extremespeed
So one-dimensional, so very deadly.
I have a Nasty Aura
Nature: Timid
EVs: 252 sp attack and speed, 4 hp
@: Life Orb
Nasty Plot
Aura Sphere
Dark Pulse/Shadow Ball
Vacuum Wave
Pretty much the same thing.
Auragility
Nature: Modest|Adamant
EVs: 252 speed, 4 hp, 252 attack|sp attack
@: Life Orb
Agility
Close Combat/Hi Jump Kick|Aura Sphere
Crunch|Dark Pulse/Shadow Ball
Ice Punch/Stone Edge|Dragon Pulse/Psychic/Hidden Power Ice
Yup
Mixed Aura (gimmick)
Nature: Speed booster that doesn't drop an attacking stat
EVs: 252 speed, 128 attack and special attack
@: Life Orb
Work Up
Aura Sphere|Close Combat/Hi Jump Kick
Crunch|Shadow Ball/Dark Pulse
Extremespeed
This set is so very simple, but it is lacking in power immensely. That is the very reason why this set is a gimmick. However, after a few Work Up boosts, this set becomes incredibly deadly.
Now, these next sets are as gimmicky as you can get. Don't use them unless you are just having fun and not taking things seriously.
Auragility Sword
Nature: Jolly/Adamant
EVs: 252 attack and speed, 4 hp
@: Life Orb
Swords Dance
Agility
Close Combat
Crunch
If you, by some crazy miracle, manage to pull off both Swords Dance and Agility, Lucario will be terrifying.
Nasty Auragility
Nature: Timid/Modest
EVs: 252 sp attack and speed, 4 hp
@: Life Orb
Agility
Nasty Plot
Aura Sphere
Dark Pulse/Shadow Ball
Same as last, only for special attacking.
Mixed Auragility (super gimmick)
Nature: Don't lower your attack, sp attack, or speed.
EVs: 252 attack and special attack, 4 speed
@: Life Orb
Agility
Work Up
Aura Sphere|Close Combat
Crunch|Shadow Ball/Dark Pulse
Unless you square off against a stall team, this set will never be pulled off successfully. However, it is an amazing anti-stall team set.