I've been having tremendous success utilizing Mega Charizard Y! I haven't really experienced Mega Charizard X, so I won't comment on it at all. But here are my thoughts on Mega Charizard Y:
Ok, so I've been playing around with MixMegaZard Y, and holy crap this thing is a train of mass destructon. Here is the set I've been using:
Charizard @ Charizardite Y
Ability: Blaze
EVs: 252 Spd / 252 SAtk / 4 Atk
Mild Nature
- Dragon Dance
- Fire Blast
- Air Slash / Roost
- Earthquake
I love this set because it catches nearly everybody off guard. People see Dragon Dance and assume I am a noob that is using physical Charizard Y, but that simply isn’t the case! It just seems odd, as people just naturally think I will be nuking then switching. This set is to try and keep Charizard in longer than just four turns and then switch out. This set has longevity, despite the lack of recovery if you don’t use Roost. Air Slash is put first simply because it hits Fighting-types hard, but you shouldn’t be too too worried about them. Fire Blast hits everything except for the various Dragon/Flying-types and bulky Water-types, which aren’t too common nowadays anyways. Fire/Ground get really good coverage, only being resisted by itself, other Fire/Flying types, Dragon/Flying types, Hydreigon, Gyarados, and Rock/Flying types. This isn’t that bad considering you have teammates for a reason, and besides, you can always switch out. It isn’t especially hard to boost, as things switch away in fear of it roasting them to death. Here are some calcs to show Earthquake’s worth:
+1 4 Atk Mega Charizard Y Earthquake vs. 252 HP / 0 Def Heatran: 428-504 (110.8 - 130.5%)
[Easy OHKO]
+1 4 Atk Mega Charizard Y Earthquake vs. 252 HP / 0 Def Tyranitar: 206-244 (50.9 - 60.3%)
[Clean 2HKO]
+1 4 Atk Mega Charizard Y Earthquake vs. 252 HP / 0 Def Mega Tyranitar: 158-186 (39.1 - 46%)
[Ehh, don’t stay in on Mega Tyranitar]
+1 4 Atk Mega Charizard Y Earthquake vs. 0 HP / 0 Def Tyrantrum: 192-228 (62.9 - 74.7%)
[Easy 2HKO]
These are only a few, but if you need more I can show them for whatever you’d like honestly. I am still wishing you had more moves, but yeah. Dragon Dance is mandatory for 1.) Surprise, and 2.) Speed. It does have lackluster Speed, so this is very helpful. I am still using this set as the primary set:
Charizard @ Charizardite Y
Ability: Blaze
EVs: 252 Spd / 252 SAtk / 4 Def
Timid Nature
- Air Slash
- Fire Blast
- Solar Beam
- Hidden Power [Ice]
All-out attacker is my personal favorite, as you get superb coverage that can easily allow you to clean up the opposition. Overall, I think Mega Charizard Y is shaping up to be the better form, but I have yet to test Mega Charizard X.