Lucario as a (shaky)
Check
Lucario @ Life Orb
Ability: Justified
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Swords Dance
- Close Combat
- Extreme Speed
- Iron Tail / Earthquake / whatever filler move
If M-beedrill has Knock Off, then Lucario can come in on anything and deal a good amount of damage (OHKO with rocks) with ES. If M-Beedrill has Drill Run though, Lucario has to wait until M-Beedrill has entered the field when rocks are up, switching in on anything bar Drill Run and then OHKO back with ES.
Calcs:
252 Atk Adaptability Mega Beedrill U-turn vs. 0 HP / 4 Def Lucario: 56-67 (19.9 - 23.8%) -- guaranteed 5HKO after Stealth Rock
252 Atk Mega Beedrill Knock Off (97.5 BP) vs. 0 HP / 4 Def Lucario: 78-92 (27.7 - 32.7%) -- 0.5% chance to 3HKO after Stealth Rock
252 Atk Mega Beedrill Drill Run vs. 0 HP / 4 Def Lucario: 260-306 (92.5 - 108.8%) -- 68.8% chance to OHKO after Stealth Rock (don't switch on this)
252+ Atk Life Orb Lucario Extreme Speed vs. 0 HP / 0 Def Mega Beedrill: 225-265 (83 - 97.7%) -- guaranteed OHKO after Stealth Rock
And after having its LO Knocked Off:
+1 252+ Atk Lucario Extreme Speed vs. 0 HP / 0 Def Mega Beedrill: 260-306 (95.9 - 112.9%) -- 75% chance to OHKO (guaranteed one with rocks up)