How does Lucario have an "easy time setting up?" What can he force out? Also, a common mistake made is to let Lucario force something out if you indeed have something that can be OHKOed by +0 Lucario out. It's better to sacrifice something to cripple it. If it uses SD, you can kill it with Excadrill or Tyranitar or paralyze it or something. Let's see what Lucario can set up on from the top 50:
Let's play might revenge kill, but can't switch into it at all!
Here are my responses to your "reasonings" (by that, I mean your madness)
Rotom-W: Wisp does threaten Lucario...if it's Physical.
Aegislash: Dark Pulse, Shadow Ball, Crunch...
Talonflame: If you're going to say Priority, Lucario wins thanks to ExtremeSpeed.
Genesect: dat Close Combat and Vacuum Wave
Greninja: No, Vacuum Wave
Charizard: Gets hurt easily anyways.
Lucario: FUCKING MIRROR MATCH
Heatran: Close Combat
Gliscor: Ice Punch
Garchomp: Ice Punch
Azumarill: Flash Cannon is a thing, you know...
Scizor: Obviously
Ferrothorn: Also obviously
Tyranitar: Never depends. That Close Combat will do it.
Conkeldurr: Eh. Mega Lucario obviously wouldn't try. Conkeldurr is a decentishish (not really) check/Revenge Killer, but nothing more.
Excadrill: Never depends. The Close Combat...
Dragonite: That first Ice Punch is stil going to hurt...
Venusaur: Only a select few Pokemon break Venusaur anyways. Speaking of...
252 SpA Adaptability Mega Lucario Flash Cannon vs. 252 HP / 4 SpD Mega Venusaur: 158-186 (43.4 - 51%) -- 5.9% chance to 2HKO
That's at a neutral attack. That's also considering that Sleep Powder can miss. Hope your synthesis works and that you've already Mega Evolved.
Mandibuzz: Whirlwind is NOT an answer to stopping a Pokemon.
Gengar: Bullet Punch with Adaptability...
Espeon: Bulet Punch with Adaptability.
Mamoswine: DETAILS! PUT IN DETAILS! Close Combat, Vacuum Wave, Bullet Punch, Flash Cannon?
Goodra: 252 Atk Adaptability Mega Lucario Close Combat vs. 252 HP / 252+ Def Goodra: 256-302 (66.6 - 78.6%) -- guaranteed 2HKO
Make it +2 and read the note below the entire list.
Alakazam: ExtremeSpeed says hi?
Landorus-T: -1 252 Atk Mega Lucario Ice Punch vs. 252 HP / 0 Def Landorus-T: 260-308 (68 - 80.6%) -- guaranteed 2HKO
First you gotta switch in.
Togekiss: No, Flash Cannon and Bullet Punch
Skarmory: Didn't we go through this before?
Breloom: Logic is backwards here (see below note).
Infernape: I'm sorry, but ExtremeSpeed?
Volcarona: DETAILS DETAILS DETAILS
Gyarados: As close as it gets, yet still falls unless this is an Assault Vest/ResTalk set. Those are your only options, yet Mega Skywalker can still set up.
Latios: Good luck with that Dark Pulse and Shadow Ball.
Mawile: Good luck tanking Close Combat
Trevenant: No. Shadow Ball.
Cloyster: Close Combat then ExtremeSpeed says no.
Pinsir: ExtremeSpeed, Ice Punch...
Blissey: Umm...obviously.
Sableye: Good luck with that Flash Cannon.
Smeargle: Never bring up Smeargle, even when talking Top 50.
Sylveon: ...no arguments here.
Klefki: Close Combat tanking.
Clefable: Bullet Punch and Flash Cannon.
Donphan: NO! We are NOT bringing up Elephant of Lame here...
Galvantula: Umm...coverage move because Galvantula is frail?
Starmie: Is always faster, eh? I guess Starmie can outspeed ExtremeSpeed.
Tentacruel: Is this really the best you can think of?
Forretress: ...not going to argue.
Bisharp: ALWAYS RUNS BECAUSE OF FIGHT-TYPE MOVES!
Salamence: Ice Punch
Thundurus: Ice Punch
Side Note: Now...all of these "threats" that you say...now imagine that you have to
switch them into Mega Lucario...GOOD LUCK. If you're going to post here, listen to what everybody says. We've been through this...