Full move sets would've been appreciated for each Pokemon.
Mega Mewtwo X is powerful enough that it doesn't need Attack boosts Baton Passed to it. It also has its own Attack-boosting move in Bulk Up. And it's an Uber, meaning you can't use it in standard play (Smogon OU, though it's okay in Wi-Fi/Battle Spot).
Wash Rotom should look like either of these:
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Pain Split/Rest
Nature: Bold
EVs: 248 HP/216 Def/44 Spe
Item: Leftovers
or
-Volt Switch
-Hydro Pump
-Will-o-Wisp/Pain Split
-Hidden Power (Ice)/Thunderbolt
Nature: Modest
EVs: 228 HP/60 SAtk/220 Spe
Item: Leftovers
or
-Volt Switch
-Hydro Pump
-Hidden Power (Ice)/Thunderbolt
-Trick
Nature: Timid/Modest
EVs: 4 Def/252 SAtk/252 Spe
Item: Choice Scarf
Tyrantrum is really outclassed in OU because Tyranitar and Ferrothorn do what it can do better, whether it's Dragon Dancing, hitting threats hard or supporting the team:
Ferrothorn:
-Leech Seed
-Protect
-Gyro Ball/Thunder Wave
-Power Whip/Stealth Rock/Spikes
Nature: Relaxed/Impish
EVs: 248 HP/252 Def/8 SDef
Item: Leftovers/Rocky Helmet
Ability: Iron Barbs
or
-Stealth Rock/Spikes
-Leech Seed
-Gyro Ball/Thunder Wave
-Power Whip/Protect
Nature: Relaxed
EVs: 248 HP/52 Def/208 SDef
Item: Leftovers
Ability: Iron Barbs
Aegislash should look like either of these ones:
-Substitute
-Toxic
-Shadow Ball
-King's Shield
Nature: Modest
EVs: 244 HP/252 SAtk/12 Spe
Item: Leftovers
or
-Shadow Ball
-Sacred Sword
-Iron Head/Shadow Sneak/Pursuit
-King's Shield
Nature: Quiet
EVs: 244 HP/252 SAtk/12 Spe
Item: Leftovers
or
-Shadow Ball
-Flash Cannon
-Sacred Sword
-Shadow Sneak/Pursuit
Nature: Hasty/Naive
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb/Spooky Plate/Spell Tag
or
-Swords Dance
-Shadow Sneak
-Iron Head/Shadow Claw
-Sacred Sword/Head Smash
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Life Orb
or
-Autotomize
-Shadow Ball
-Hidden Power (Ice)
-Sacred Sword/Iron Head/Flash Cannon
Nature: Rash/Modest
EVs: 124 Atk/252 SAtk/132 Spe
Item: Life Orb/Weakness Policy
As I said, Mega Mewtwo X is strong and fast enough that it doesn't have to rely on Baton Passing to succeed. Baton Pass Scizor is best played in dedicated Baton Pass teams, so I think Scolipede should be in this one:
-Megahorn
-Spikes/Toxic Spikes
-Swords Dance/Toxic Spikes
-Earthquake/Rock Slide/Baton Pass
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Focus Sash
Ability: Speed Boost
or
-Swords Dance
-Protect/Megahorn
-Substitute/Megahorn
-Baton Pass
Nature: Timid/Jolly
EVs: 248 HP/208 Def/52 Spe
Item: Black Sludge/Mental Herb
Ability: Speed Boost
Mega Mewtwo X should look something like this (take note you need Poke Bank and Black 2/White 2 for these moves):
-Low Kick
-Zen Headbutt/Earthquake
-Ice Beam/Stone Edge
-Taunt
Nature: Naive/Jolly
EVs: 252 Atk/4 SAtk/252 Spe
Item: Mewtwonite X
or
-Bulk Up
-Drain Punch/Low Kick
-Zen Headbutt/Rock Slide
-Taunt/Rock Slide
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Mewotwonite X
Or if your opponents complain that you have a Mewtwo with you, settle for Mega Heracross. While it's significantly slower than Mewtwo, it appreciates the Speed boosts from Scolipede at the cost of making you more vulnerable to Talonflame:
-Pin Missile
-Close Combat/Swords Dance
-Rock Blast
-Earthquake
Nature: Adamant
EVs: 40 HP/252 Atk/216 Spe
Item: Heracronite
Ability: Moxie/Guts
The best Blissey can do is this:
-Aromatherapy/Heal Bell
-Seismic Toss/Flamethrower
-Soft-Boiled
-Toxic/Thunder Wave
Nature: Bold
EVs: 4 HP/252 Def/252 SDef
Item: Leftovers
Ability: Natural Cure