Rating my team?

[Meksal]

I already beat the game, including the elite four, I would like to know how my team is, what do you think? I also would like to know which one I should replace for a level 70 Mewtwo, if I should replace at all?

Zygarde
Level 70
HP 237
Holding Luck Insence
<Dark> Crunch
<Ground> Earthquake
<Normal> Camouflage
<Dragon> Dragon Pulse
Attack 158
Defense 196
Sp. Atk 140
Sp. Def 159
Speed 140
Aura Break
The effects of "Aura" Abilities are reversed.

Blastoise (Can turn mega)
Level 66
HP 200
Holding Blastoisinite
<Water> Waterfall
<Water> Hydro Pump
<Water> Surf
<Water> Aqua Tail
Attack 152
Defense 144
Sp. Atk 133
Sp. Def 144
Speed 152
Torrent
Powers up water type moves when the Pokemon is in trouble.

Blaziken (Can turn mega)
Level 86
HP 245
Holding Blazikenite
<Fighting> Double Kick
<Flying> Brave Bird
<Fire> Blaze Kick
<Fighting> Sky Uppercut
Attack 269
Defense 156
Sp. Atk 223
Sp. Def 142
Speed 170
Speed Boost
It's speed stat is gradually boosted.

Xerneas
Level 63
HP 257
Holding Big Root
<Dark> Night Slash
<Grass> Horn Leech
<Fairy> Moonblast
<Bug> Megahorn
Attack 170
Defense 150
Sp. Atk 221
Sp. Def 155
Speed 157
Fairy Aura
Powers up each Pokemon's Fairy-type moves.

Delphox
Level 66
HP 193
Holding nothing
<Fire> Flamethrower
<Fire> Fire Blast
<Fire> Mystical Fire
<Psychic> Psyshock
Attack 138
Defense 137
Sp. Atk 162
Sp. Def 147
Speed 173
Blaze
Powers up Fire-type moves when the Pokemon is in trouble.

Aurorus
Level 64
HP 239
Holding nothing
<Normal> Take Down <Ice because of ability>
<Ice> Avalanche
<Ice> Ice Beam
<Normal> Hyper Beam <Ice because of ability>
Attack 146
Defense 125
Sp. Atk 158
Sp. Def 123
Speed 118
Refridgerate
Normal type moves become ice type moves​

 

[PlatinumDude]

There's no need to say their stats themselves here. Saying EVs and natures is more important.

Even though Zygarde isn't as strong as other Dragons, it has two setup moves that make it useful in conjunction with its good bulk:
-Substitute
-Coil
-Earthquake
-Dragon Tail
Nature: Careful
EVs: 252 HP/4 Def/252 SDef
Item: Leftovers

or
-Dragon Dance
-Outrage
-Earthquake
-Stone Edge/Extreme Speed
Nature: Adamant
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb/Lum Berry

or
-Substitute
-Glare
-Earthquake
-Dragon Tail
Nature: Impish
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers

Blaziken learns a stronger Fighting STAB in High Jump Kick and a stronger Fire STAB in Flare Blitz. Take note that it's an Uber in Smogon play, but it's okay to use in Battle Spot/Wi-Fi battles:
-Flare Blitz
-High Jump Kick
-Swords Dance/Protect
-Knock Off/Shadow Claw/Stone Edge/Protect
Nature: Adamant/Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb/Blazikenite
Ability: Speed Boost

Take note that you can only Mega Evolve 1 Pokemon per battle. Blastoise is only good in its Mega form:
-Water Pulse/Scald/Hydro Pump
-Dark Pulse
-Aura Sphere/Ice Beam
-Rapid Spin
Nature: Modest
EVs: 252 HP/252 SAtk/4 SDef
Item: Blastoisinite

Delphox and Aurorus aren't good Pokemon, tbh. There's a lot of Pokemon that can do their jobs better. In fact, there are so many of them that it's hard for me to pinpoint which replacement suits the team. However, Delphox is only good in in-game situations.

 

[Meksal]

So I kicked Aurorus off my team for Mewtwo, still always lose in battle spot.