Okay here we go with VGC sets for Lucario. Lucario to be honest doesn't have much going for it in 2017. Base 90 Speed coupled with base 70 defenses all around mean that Lucario has a hard time dealing with common threats like Garchomp, Tapu Lele, and Tapu Koko. Intimidate is another thing that hinders its usage. Jolly Krookodile can easily outspeed and KO with a Tectonic Rage, Gyarados is safe to sit pretty in front of Lucario and set up in its face or go for a KO with Hydro Vortex. And Arcanine... yeah I don't even need to talk about that matchup for Lucario. So how do you use it? Well I've spent some time with the LATAM winner, Ashton Cox, and his sister, Gwenn and Gwenn has been running Lucario for a while on a Torkoal Lilligant Trick Room team. The idea is to use Lucario's access to Final Gambit along with a Choice Scarf to pair well with Oranguru. You can score a knockout onto an opponent if it's frail enough then use Trick Room in the same turn. Then bring in Torkoal or Snorlax to do what they do best and abuse the speed inversions. If that isn't really your cup of tea, then Lucario can have some niche uses. As a Fighting type, STAB Close Combat/Hi Jump Kick/Low Kick in the current meta is extremely valuable to counter Snorlax. Feint is also valuable in a format where Protect runs rampant, Poison Jab does massive damage to Tapus when it connects, Bulldoze is a pretty niche form of speed control, and Extreme Speed, as we have seen by even bulky variants of Arcanine, is great for picking off weakened threats outside of Psychic Terrain (same goes for Bullet Punch). Lucario even gets Follow Me and Blaze Kick as Egg Moves! However, Hariyama, Buzzwole, and Pheromosa typically do better as a Fighting type for your team as Hariyama, while slow and bulky, can still outspeed Snorlax and isn't weak to High Horsepower. Guts boosted Close Combat also hits harder than Hi Jump Kick from Lucario. Also, Hariyama gets Feint, Poison Jab, and Bulldoze too, as well as Fake Out. Buzzwole can perform on about the same level as Lucario. So why is Buzzwole preferred? Access to Ice Punch, better physical attack, and a more usable secondary STAB in Leech Life on a physical set it apart by being able to counter Garchomp, more easily handle Arcanine, and recover itself to an extent with Leech Life. Both are subpar without a good speed boost like Tailwind or a Choice Scarf. Pheromosa and Lucario share a common problem in that both are frail. Sure Lucario has better defenses, but dangerous attackers like the Tapus, Arcanine, and UBs can still make short work of them with presented with the opportunity. And unfortunately for Lucario, that's the big selling point. Pheromosa is blisteringly fast at bast 151 speed, and only weather speed boosters and Scarf Pokémon can outspeed it, leaving little opportunity for opponents to fight back without eating a hit first. Lucario is both frail and slow and weak to the same things as Pheromosa and so much more, meaning opponents have so many opportunities to KO Lucario. Plus Buzzwole and Pheromosa are rewarded for KOs with a Beast Boost, whereas Lucario lacks a good ability (unless you're into Inner Focus). When opponents see Lucario in team preview, it's just standard to expect a Scarf and Final Gambit in this format. Lucario is not able to surprise opponents well because of this, as any other item on Lucario can be very detrimental to it (other than maybe a Z move), so if your opponent figures out Lucario doesn't have a Scarf, it simply becomes that much easier to deal with. All said and done, Lucario does have its niche like I explained earlier but finds it very hard to perform outside of it with so much competition for a potentially dangerous fighting type slot that it's hard to justify using it outside of a Scarf Final Gambit set.