I was talking more about how you give altaria defensive EVs and don't for salamence, metagross, or gallade when calculating the damage done by altaria.
edit: Just goofing off with ev's and I have to say, m-altaria is a very viable choice against m-salamence
212+ SpAtk Pixilate Mega Altaria Hyper Voice vs. 100 HP/116 SpDef Aerilate Mega Salamence: 182 - 216 (99.5 - 118%) -- 87.5% chance to OHKO
that's the absolute minimum you'd have to run on salamence to not be a guaranteed OHKO.
edit 2: I just realized in both mine and eeyores calculations the box for double battle was not clicked.
212+ SpAtk Pixilate Mega Altaria Hyper Voice vs. 0 HP/0 SpDef Aerilate Mega Salamence: 152 - 182 (89.4 - 107.1%) -- 43.8% chance to OHKO
This is from having the doubles/triples box checked
with it not being naive, yes. I had the doubles box clicked for the naive one as well.
Both Draco Meteor and Ice Beam have a higher chance to OHKO though
0 SpA Mega Altaria Draco Meteor vs. 0 HP / 0 SpD Mega Salamence: 174-206 (102.3 - 121.1%) -- guaranteed OHKO
52 SpA Mega Altaria Ice Beam vs. 0 HP / 0 SpD Mega Salamence: 172-204 (101.1 - 120%) -- guaranteed OHKO
I was only making my calcs off of Hyper Voice.
even at full HP investment
156 SpA Mega Altaria Draco Meteor vs. 252 HP / 0 SpD Mega Salamence: 204-240 (100.9 - 118.8%) -- guaranteed OHKO
52+ SpA Mega Altaria Draco Meteor vs. 252 HP / 0 SpD Mega Salamence: 204-240 (100.9 - 118.8%) -- guaranteed OHKO
140+ SpA Mega Altaria Ice Beam vs. 252 HP / 0 SpD Mega Salamence: 204-240 (100.9 - 118.8%) -- guaranteed OHKO
At Altaria's max special attack investment, Salamence must run full HP and 164 special defense not to be OHKOed by Draco Meteor,
252+ SpA Mega Altaria Draco Meteor vs. 252 HP / 164 SpD Mega Salamence: 200-236 (99 - 116.8%) -- 87.5% chance to OHKO
92 Special Defense not to be OHKOed by Ice Beam
252+ SpA Mega Altaria Ice Beam vs. 252 HP / 92 SpD Mega Salamence: 200-236 (99 - 116.8%) -- 87.5% chance to OHKO
However, Hyper Voice doesn't do the same
252+ SpA Pixilate Mega Altaria Hyper Voice vs. 0 HP / 0 SpD Mega Salamence: 162-192 (95.2 - 112.9%) -- 68.8% chance to OHKO
So, I did Hyper Voice as a base, as it'll be the most likely to be run on all Altaria's, but It has 2 more consistent kills on Salamence as well.
TL;DR, there's a LOT of potential with Altaria, and not necessarily in Hyper Voice, though that is a multi-opponent hitter. The problem is 4 move-slot syndrome with her,
You need Hyper Voice, and should run Fire Blast for Steels.
so you have one more slot before the obligatory Protect (mostly for your partner to deal with Scizor or MegaMence)
Should it be Roost, for reliable HP recovery, Ice Beam for the most neutral damage and coverage, to hit Lando-T, and Gliscor, ect, or should it be Draco for the highest Damage output.