Mega-Venu team

Venusaur @ Venusaurite
Ability: Chlorophyll
EVs: 248 HP / 236 Def / 4 SpD / 20 Spe
Bold Nature
IVs: 0 Atk
- Giga Drain
- Sludge Bomb
- Synthesis
- Leech Seed

The spread dodges the 2hko from +3 manaphy ice beam after rocks factoring the recovery from giga drain, the rest maximizes the physical bulk and speed creeps the standard spread

Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
- Lava Plume
- Toxic
- Taunt
- Stealth Rock

Latios @ Life Orb
Ability: Levitate
EVs: 8 HP / 32 Def / 216 SpA / 252 Spe
Timid Nature
- Draco Meteor
- Psyshock
- Roost
- Defog

Ev spread takes QA from +2 jolly pinsir after rocks, can be situationally useful against xtrashine's birdspam. Still is a tough matchup.

Landorus-Therian @ Choice Scarf
Ability: Intimidate
EVs: 252 Atk / 24 Def / 232 Spe
Jolly Nature
- Earthquake
- U-turn
- Stone Edge
- Superpower

Bisharp @ Black Glasses
Ability: Defiant
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Knock Off
- Swords Dance
- Iron Head
- Sucker Punch

Keldeo-Resolute @ Choice Specs
Ability: Justified
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Scald
- Secret Sword
- Hydro Pump
- Icy Wind

The last slot is a toss up between hp bug (this team has a hard time with offensive starmie) and icy wind. The latter allows keldeo to remove latios and dragonite (it has some setup opportunities vs this team)

Mega-zard-x team

Charizard-Mega-X @ Charizardite X
Ability: Tough Claws
EVs: 156 HP / 188 Atk / 4 SpD / 160 Spe
Adamant Nature
- Flare Blitz
- Dragon Claw
- Roost
- Dragon Dance

Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 88 Def / 168 SpD
Relaxed Nature
IVs: 0 Spe
- Gyro Ball
- Leech Seed
- Stealth Rock
- Protect

Latias @ Life Orb
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Draco Meteor
- Psychic
- Defog
- Healing Wish

Landorus-Therian @ Choice Scarf
Ability: Intimidate
EVs: 232 Atk / 24 Def / 252 Spe
- Earthquake
- U-turn
- Stone Edge
- Superpower

Weavile @ Choice Band
Ability: Pressure
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Ice Shard
- Icicle Crash
- Knock Off
- Low Kick

Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 172 Def / 88 Spe
Bold Nature
IVs: 0 Atk
- Volt Switch
- Hydro Pump
- Will-O-Wisp
- Pain Split

http://www.smogon.com/forums/threads/m-charizard-x-balance.3543537/#post-6567285 This is the rmt in case you're wondering about ev spreads, etc...Band/LO are both good on weavile, but they come with their side effects. I prefer band bc LO wears you down too fast, especially with rocks up. Speed investiment on rotom outspeed jolly crawdaunt.

Mega-hera team

Heracross-Mega @ Heracronite
Ability: Guts
EVs: 196 HP / 176 Atk / 136 Spe
Adamant Nature
- Swords Dance
- Close Combat
- Pin Missile
- Rock Blast

Kills clef at +2 (also the evs in Atk are a jump point) speed is for adamant bish b4 mega evo.

Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Lava Plume
- Toxic
- Taunt
- Stealth Rock

Latios @ Life Orb
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Draco Meteor
- Psychic
- Roost
- Defog

Thundurus @ Life Orb
Ability: Defiant
EVs: 68 Atk / 188 SpA / 252 Spe
Naive Nature
- Thunderbolt
- Knock Off
- Superpower
- Hidden Power [Ice]

Jirachi @ Choice Scarf
Ability: Serene Grace
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Iron Head
- U-turn
- Fire Punch
- Healing Wish

Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 172 Def / 88 Spe
Bold Nature
IVs: 0 Atk
- Volt Switch
- Hydro Pump
- Thunder Wave
- Pain Split

Scarflando over thundurus is an option to better deal with fast electrics, but I don't like having two scarfer on the same team. Rotom has twave to lure and paralyze zard-x. Mega-diancie and mega zam are a huge threats, probably this team can be tweaked further but don't have any ideas.