Hey! InfernapeBurn here. This is my second time answering this question, if you look in the comments you can see what happened the first time. And I was all ready to click Add Answer, too. Oh well. Try again.
Anyway, the team is good, but still imperfect. Although, what team is perfect. The one that 6-0's with no damage every time, I suppose.:P. However, I'll try to get it as close to what I consider perfect as I possibly can. Here we go!
Mega Aggron:
First off, replace Rock Slide for Stone Edge. The power is preferred over the still shaky accuracy that Rock Slide grants. If you're still skeptical, check this out: Stone Edge has 80% accuracy, meaning that it will hit 8 turns out of 10, on average, for a 100 BP strike for each hit. Multiply these together, and you get 800 BP in 10 turns. Rock Slide, on the other hand, has 75 BP and an accuracy of 90%, for hitting 9 turns out of 10, on average. This yields only 675 BP in 10 turns. On top of that, Stone Edge has a raised critical hit ratio. I think we have a clear winner here. Also, on a full-offense Aggron such as this one, Thunder Wave is not really the greatest. Replace for one of his greatest assets: Fairy coverage in a STAB Steel move, Iron Head.
Dragonite:
Like Nichalas said, replace Outrage for Dragon Claw. You don't want to be trapped into the move when a Fairy type comes in to destroy his derpy-looking face. And the, as Confusion from Outrage is no longer an issue, replace the now-useless Lum Berry for a Weakness Policy. Multiscale will ensure you survive at least one super effective attack, then boosting your already great Attack to ridiculous levels. You can predict an Ice Beam, Stone Edge, Moonblast, etc., and use Dragon Dance to sweep from there. In case your Multiscale is broken by some non-super effective attack, consider replacing Earthquake for Roost, to heal you right back to Multiscale range. This will render you incapable against Klefki and Mega Mawile, though, so beware.
Keldeo:
I don't know much about Keldeo, nor do I pretend to. ATM you seem to have a slight Electric weakness that Keldeo is not helping with. Possibly replace with one that I know slightly more about and love immensely, Eelektross.
Eelektross@Assault Vest
Ability: Levitate
EV's: 252 SAk / 252 HP / 4 SDf
Modest Nature
-Thunderbolt
-Volt Switch
-Grass Knot
-Flamethrower
My God, is this guy underrated. Great Attack, good Special Attack, and good bulk to boot. Since you have more physical than special attackers, I gave a Special set here. Thunderbolt is your main STAB. Volt Switch will help you out of sticky situations with Mold Breakers like Haxorus and Mega Gyarados. Grass Knot will help with Ground- and Rock-types. Flamethrower hits Steel-, Bug-, and Grass-types like Ferrothorn, Scizor, Forretress, and Excadrill. The Assault Vest helps with his Special bulk. With these moves, you won't be able to touch Dragons, so be careful.
Gardevoir:
Hate to break it to ya but Gardevoir is not so good without its Mega, and its speed is kinda... iffy. Also, if you use Talonflame, you will need a Rapid Spinner. I have three options lined up for you to choose from.
Option A: Starmie
Starmie@Life Orb
Ability: Natural Cure
EV's: 252 SAk / 252 Spd / 4 SDf
Timid Nature
-Surf
-Psychic/Psyshock
-Rapid Spin
-Thunderbolt/Ice Beam
A quick Water/Psychic type, Starmie is your man if you want something with good Special Attack and Speed, a useable movepool, access to Rapid Spin, and decent bulk. Well, it's technically genderless, so not really a man... but you catch my drift. Surf over Hydro Pump because, if we apply the math used on Aggron's description, 90 BP and perfect accuracy for hitting 10 times in 10 turns, for 900 BP in 10 turns. Hydro Pump, on the other hand, has 110 BP and only 80% accuracy, hitting 8 times in 10 turns, gives 880 BP across 10 turns. Psychic/Psyshock will be your secondary STAB. The former is more powerful, but the latter helps with being faux-mixed, as it targets Physical Defense rather than Special. Rapid Spin is the crux of the set. Thunderbolt/Ice Beam comes down to preference really, whether you like coverage vs. Grass and Dragon or Water Pokémon. This set will open up another Electric weakness, so be wary of them if you choose this set.
Option B: Claydol
Claydol@Leftovers
Ability: Levitate
EV's: 252 SAk/252 HP/4 Def
Calm Nature
-Psychic
-Earth Power
-Calm Mind/Cosmic Power
-AncientPower/Calm Mind
"Hey! Hey guys! You know that one clay doll Pokémon we couldn't think of a name for? Well, I've got a great one! Claydol!"
Rousing applause from all Employee receives a promotion
Ah, literal Pokenames. Anyway, about the set. This guy is bulkier than your other two option, but packs less of a punch. The great thing about Levitate on a Rapid Spinner is that he'll take no damage from Spikes and is not poisoned by Toxic Spikes, and this one's also a Ground-type, so he takes less damage from SR. Psychic and Earth Power are your dual STABs. Calm Mind helps with hitting harder and taking less damage itself and Cosmic Power boosts both defensive stats. AncientPower is decent coverage as well as having a chance to boost all stats. Also, it's immune to Electric, so Keldeo maybe kept with this one.
Option 3: Espeon
Espeon@Life Orb
Ability: Magic Bounce
EV's: 252 SAk/252 Spd/4 HP
Timid Nature
-Psychic/Psyshock
-Grass Knot
-Shadow Ball
-Dazzling Gleam
Okay, okay, so it's not technically a Rapid Spinner. But who cares, right? It has Magic Bounce, and if you play it right, that can be just as good or even better. The debate between Psychic and Psyshock is the same as before. Grass Knot can help with Water-, Ground-, and Rock-types like Mega Blastoise, Excadrill, and Gastrodon. Shadow Ball can helps with other Psychics and pesky Ghosts. Dazzling Gleam will destroy opposing Dragon- and Dark- types, as well as the rare Scrafty.
Talonflame:
Fine, but if you like the idea of Espeon but don't like the fact that once Rocks are up your Talonflame is basically useless, or want to keep Gardevoir, Infernape is a great Fire type with no SR weakness. As Infernape is my mascot Pokémon, as well as my favorite, I have quite a few sets for him. One is:
LO Specialnape
Infernape@Life Orb
EV's: 252 Spd, 252 SAk, 4 HP
Modest Nature
Blaze
-Fire Blast/Flamethrower
-Grass Knot
-Focus Blast
-Nasty Plot
Intellectual Monkey
Infernape@Choice Specs
EV's: 252 Spd, 252 SAk, 4 HP
Modest Nature
Blaze
-Flamethrower/Fire Blast/Overheat
-Focus Blast
-Grass Knot
-Hidden Power {WHATEVER}/Vacuum Wave
AV Flaming Psycho Monkey
Infernape@Assault Vest
EV's: 252 Spd, 128 SAk, 128 Atk
Naive Nature
Blaze
-Fire Blast/Flamethrower
-Grass Knot
-Close Combat
-U-Turn/Stone Edge/Shadow Claw
Sniper Ape
Infernape@Wide Lens
EV's: 252 Spd, 128 SAk, 128 Atk
Hasty/Naive Nature
Blaze
-Fire Blast
-Stone Edge
-Focus Blast
-Blaze Kick
Don't feel like writing descriptions right now, and these are fairly simple so... yeah. I'll just let you figure these out. Shouldn't be too hard.
Mamoswine:
Mamo's Special Attack is not so hot. Although, he is an Ice type, so maybe it is hot? I don't know. Anyway, on that note Freeze Dry should be replaced for Stone Edge. As you no longer have any Special attacks, tat stat is useless, so it should be decreased and your nature should be Adamant. The last 4 EV's should be put into Speed, in case any other Mamoswines come in with the same spread but 4 in Def instead. Also, Consider a Choice Band item.
God, that took forever to type. I wouldn't be surprised if I got one or two or 2,988 TL;DR's. :P But anyway,
There you go! Hope I helped!
-Infernapeburn
