3 Man Team Advice?

[RussianBoss]

Hi. I'm trying to make a 3 man Pokemon Y team for competitive single battles. This is my team so far:

Gengar-
Nature: Timid
Ev: 6 hp, 252 spa, 252 spe
Item: Gengarite

• 
  Shadow Ball
  Dazzling Gleam
  Thunderbolt
  ???

Crobat-
Nature: Adamant
Ev: 6 hp, 252 atk, 252 spe
Item: None

• 
  Acrobatics
  Fly
  Haze
  U-Turn

Scizor-
Nature: Adamant
Ev: 252 hp, 252 atk, 6 spe
Item: Choice Band

• 
  Bullet Punch
  U-Turn
  Swords Dance
  ???

Now I'm contemplating switching out Mega Gengar for Mega Tyranitar because Gengar is really delecate and is easily out-sped by protean Greninja's and priority shadow sneak. What do you guys think? Should I switch those two? Any other insight would be appreciated. Thanks.

 

[PlatinumDude]

Mega Gengar should make the most out of its new Shadow Tag ability. It shouldn't just hammer at walls with offensive moves alone because there's a risk it can be crippled by status. All-out offense is still viable in itself, tough Also remember that Mega Gengar outspeeds Greninja:
-Shadow Ball
-Sludge Bomb/Focus Blast
-Perish Song/Destiny Bond
-Substitute/Taunt/Protect
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Gengarite

or
-Shadow Ball
-Sludge Bomb/Focus Blast
-Substitute/Taunt
-Disable/Hypnosis
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Gengarite

or
-Shadow Ball
-Sludge Bomb
-Focus Blast
-Thunderbolt/Hidden Power (Fire)
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Gengarite

Infiltrator got buffed in Gen VI to let Crobat hit through Substitutes. Take advantage of this by making Crobat into a stallbreaker. Fly is too unreliable and predictable:
-Brave Bird
-Taunt
-U-turn/Toxic
-Roost
Nature: Jolly
EVs: 120 HP/136 Atk/252 Spe
Item: Black Sludge
Ability: Infiltrator

Note that Choice Band leaves Scizor locked into one move while it's in battle, so Swords Dance and Choice Band should be separate:
-U-turn
-Bullet Punch
-Brick Break
-Pursuit/Quick Attack
Nature: Adamant
EVs: 248 HP/252 Atk/8 SDef
Item: Choice Band
Ability: Technician

or
-Swords Dance
-Bullet Punch
-X-Scissor
-Brick Break
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Life Orb
Ability: Technician