Alright, I've been an Absol user for a very long time. Originally, I assumed, like many others... that Naïve was the best nature for Mega Absol, since 361 puts him at a great speed tier.
I'm actually here to make a compelling argument that Naughty is the preferred Nature for Mega Absol and should be listed in the set as such. The primary reason for this change is because nearly all threats to Absol above 329 speed (Absol's speed with Naughty Nature) are OHKO'ed by +2 Sucker Punch or close to it. Let's look at some calcs:
Naïve:
+2 252 Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Garchomp: 304-358 (84.9 - 100%) -- 6.3% chance to OHKO
+2 252 Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Garchomp: 304-358 (84.9 - 100%) -- 43.8% chance to OHKO after Stealth Rock
Naughty:
+2 252+ Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Garchomp: 333-393 (93 - 109.7%) -- 56.3% chance to OHKO
+2 252+ Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Garchomp: 333-393 (93 - 109.7%) -- 93.8% chance to OHKO after Stealth Rock
Naïve:
+2 252 Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Scizor: 291-343 (84.5 - 99.7%) -- guaranteed 2HKO
+2 252 Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Scizor: 291-343 (84.5 - 99.7%) -- 81.3% chance to OHKO after Stealth Rock
Naughty:
+2 252+ Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Scizor: 319-376 (92.7 - 109.3%) -- 56.3% chance to OHKO
+2 252+ Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Scizor: 319-376 (92.7 - 109.3%) -- guaranteed OHKO after Stealth Rock
Naive
+2 252 Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Mega Charizard X: 265-313 (88.9 - 105%) -- 31.3% chance to OHKO
Naughty:
+2 252+ Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Mega Charizard X: 292-345 (97.9 - 115.7%) -- 87.5% chance to OHKO
Naïve:
+2 252 Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Rotom-W: 274-324 (90.1 - 106.5%) -- 43.8% chance to OHKO
Naughty:
+2 252+ Atk Mega Absol Sucker Punch vs. 252 HP / 0 Def Rotom-W: 301-355 (99 - 116.7%) -- 93.8% chance to OHKO
Naïve:
+2 252 Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Mega Pinsir: 249-294 (91.5 - 108%) -- 50% chance to OHKO
Naughty:
+2 252+ Atk Mega Absol Sucker Punch vs. 4 HP / 0 Def Mega Pinsir: 273-322 (100.3 - 118.3%) -- guaranteed OHKO
So, who exactly are you not outspeeding or losing to with Naughty Nature? Keldeo, Terakion, and Talonflame.
Keldeo and Terakion often run scarfed sets, making them hard counters to Absol regardless. Talonflame is a valid argument to run Naïve over Naughty though. As for Mega Lucario... He will always hard counter Absol. Leaving Absol in and attempting to Fire Blast is often suicide because most M-Lucario's run Vacuum Wave. If Lucario is in the middle of a sweep. +2 Extremespeed/Bullet Punch will always OHKO Absol before it can do anything.
I posted these calcs to show that Garchomp is handled perfectly fine by Sucker Punch at +2, as well as a majority of other notable threats. And yes - with Naughty, you can still Ice Beam Gliscor and Landorus-T. You can still Play Rough every dragon except Garchomp. And you can still Fire Blast Skarmory, Ferrothorn, Forretress, M-Mawile, and Kelfki.
We need to ask ourselves if Naïve is really necessary as M-Lucario hard counters Absol anyways. What do you guys think? (I'm going to have a lot more breeding to do if Naughty is a better nature.)