You guys are forgetting that mega lucario gets adaptability. Lets say for the sake of argument MegaLucario gets around 20+ added to its attack stat [which is more than likely to happen given A) it was confirmed that its attacking stat is increasing anyway and B) GF has a fetish for power creep]. 252+ Atk Life Orb Lucario Close Combat vs. 0 HP / 0 Def Abomasnow: 632-743 (196.88 - 231.46%) -- guaranteed OHKO 252+ Atk Adaptability MegaLucario Close Combat vs. 0 HP / 0 Def Abomasnow: 728-860 (226.79 - 267.91%) -- guaranteed OHKO 252+ Atk MegaLucario ExtremeSpeed vs. 0 HP / 0 Def Abomasnow: 122-144 (38 - 44.85%) -- guaranteed 3HKO 252+ Atk Life Orb Lucario ExtremeSpeed vs. 0 HP / 0 Def Abomasnow: 140-166 (43.61 - 51.71%) -- 11.72% chance to 2HKO So yeah, statistically speaking, MegaLucario (STAB wise) is actually stronger than the regular one. Knowing GF, I'm pretty sure it's getting more than just a 20+ boost to attack lol (probably around 30 or 35). Now this is all assuming the Pokemon in question isn't allowed to hold any items, which hasn't been confirmed one way or another. For all we know, those evolution items go away once the evolution happens or can be removed once its done, and as far as I'm aware, reverse evolutions have never been a thing. So it's very likely MegaLucario is better than the normal. I'm guessing its attack is increased in exchange for a lower special attack.