A Mono-Mew team? Interesting idea...
Mew #1: Dragon Pulse doesn't have a whole lot of value here, as the opponent will be using a Dark, Bug, or Ghost type. Therefore, replace it with Shadow Ball. Also, I would get rid of Signal Beam, as it covers roughly the same types as Aura Sphere. Replace it with Nasty Plot to boost up that SAtk stat.
Mew #2: Not much I can say here. It's pretty good.
Mew #3: I would suggest Scarfing this one, and making it entirely Special, like J98 said. Teach it Aura Sphere, Shadow Ball, Flamethrower, and Psyshock. Change the EVs to 252 SAtk, 252 Spd, and 4 HP. Change the nature to Timid (+Spd, -Atk).
Mew #4: I would suggest changing the EVs to 128 HP, 128 Def, and 252 SDef. You have Will-O-Wisp to beef up your Defense, so I invested some EVs in HP. Also, why Modest when you don't have any Special moves? Change it to Calm (+SDef, -Atk). Also, replace Seismic Toss with Stealth Rock to kill Bug types that might want to kill you (I can see why you put Night Shade and Seismic Toss on, but Normal types are rare).
Mew #5: Stone Edge isn't very reliable, so replace it with Rock Slide. Also, Poison Jab doesn't have a whole lot of value, since it only covers Grass types, and most Grass types are Dual Poison... Replace it with Acrobatics for some incredible damage once the Liechi Berry kicks in.
Mew #6: Replace Swift for Charge Beam to beef up that SAtk stat.
Exportable Version
Mew @ Wise Glasses
Trait: Synchronize
EVs: 4 HP / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Shadow Ball
- Aura Sphere
- Psychic
- Nasty Plot
Mew @ Muscle Band
Trait: Synchronize
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Outrage
- Earthquake
- Zen Headbutt
- Fire Punch
Mew @ Choice Scarf
Trait: Synchronize
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Aura Sphere
- Shadow Ball
- Flamethrower
- Psyshock
Mew @ Leftovers
Trait: Synchronize
EVs: 128 HP / 128 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Stealth Rock
- Will-O-Wisp
- Night Shade
- Pain Split
Mew @ Liechi Berry
Trait: Synchronize
EVs: 56 HP / 252 Atk / 200 Spd
Jolly Nature (+Spd, -SAtk)
- Rock Slide
- Acrobatics
- Shadow Claw
- Brick Break
Mew @ Petaya Berry
Trait: Synchronize
EVs: 56 HP / 252 SAtk / 200 Spd
Timid Nature (+Spd, -Atk)
- Flamethrower
- Frost Breath
- Shadow Ball
- Charge Beam