And exactly how manyIt does, as with some investment, it can
212+ SpA Pixilate Mega Altaria Hyper Voice vs. 0 HP / 0- SpD Mega Salamence: 170-204 (100 - 120%) -- guaranteed OHKO
252 Atk Aerilate Mega Salamence Double-Edge vs. 252 HP / 0 Def Mega Altaria: 135-159 (74.1 - 87.3%) -- guaranteed 2HKO -- mixed attacker
252+ Atk Aerilate Mega Salamence Double-Edge vs. 252 HP / 0 Def Mega Altaria: 147-174 (80.7 - 95.6%) -- guaranteed 2HKO -- Physical attacker
252+ SpA Aerilate Mega Salamence Hyper Voice vs. 252 HP / 0 SpD Mega Altaria: 75-88 (41.2 - 48.3%) -- guaranteed 3HKO -- Special Attacker
See above as to why I have issue with both sets of calculationsMega Altaria needs Tailwind support-- found quite easily in Talonflame-- which then threatens with Flare Blitz. +2 speed (200 speed) means she outspeeds Mega-Mence, and OHKOs.
Yes she does fall to MegaGross, which other pokemon can take out. Suicune also has tailwind and threatens MegaGross with scald, and Mence with Ice Beam/Icy Wind. Fire Blast also usually deals a significant amount to MegaGross. Heatran also threatens MegaGross, and with Air Balloon, works pretty well as a partner
212+ SpA Mega Altaria Fire Blast vs. 0 HP / 4 SpD Mega Metagross: 110-130 (70.9 - 83.8%) -- guaranteed 2HKO
252 Atk Tough Claws Mega Metagross Bullet Punch vs. 252 HP / 44 Def Mega Altaria: 86-104 (47.2 - 57.1%) -- 91.4% chance to 2HKO
252+ Atk Tough Claws Mega Metagross Bullet Punch vs. 252 HP / 44 Def Mega Altaria: 98-116 (53.8 - 63.7%) -- guaranteed 2HKO
Meteor Mash always OHKOs.
Mega Altaria also threatens Mega Gallade pretty well
212+ SpA Pixilate Mega Altaria Hyper Voice vs. 4 HP / 0 SpD Mega Gallade: 126-150 (87.5 - 104.1%) -- 31.3% chance to OHKO
252 Atk Mega Gallade Ice Punch vs. 252 HP / 44 Def Mega Altaria: 90-108 (49.4 - 59.3%) -- 99.6% chance to 2HKO
252+ Atk Mega Gallade Ice Punch vs. 252 HP / 44 Def Mega Altaria: 100-118 (54.9 - 64.8%) -- guaranteed 2HKO
Mega Altaria should always run roost as well. So she can actually take some hits
Also, why would you not run intimidate next to her, which lowers her chance to be 2HKOed by Bullet Punch, as well as acting as a pseudo boost to her defenses? Lando-T with Rock Slide and U-turn, or Hitmontop with Wide Guard and Helping Hand, or Gyarados with Waterfall and Ice Fang? All great team options.
No, Mega Altaria isn't S rank, but she should stop being counted out
If we're going to be biased and make calculations that are unrealistic for ev spreads so that we make our points look valid then I can make just as many calculations as to why altaria is bad having it run the obvious 252/4/252 spread you used for mence, gross, and gallade.