Hey, if the Mane 6 each had their own duel monster's deck what do you think it would it be? Personally I would pick these...
Twilight - Prophecy
Pinkie - Performapal
Fluttershy - Butterspy
Rainbow - Blackwing or Speedroid
Rarity - Gem-Knight
Applejack - Unknown
What about you guys?

4556067
If the main six had decks in the yugioh world, here's what I think they'd have.

Twilight - Prophecy (Agreed)
Pinkie - Either Performapals or Madolches
Fluttershy - Raccoons
Rainbow - Either Mecha Phantom Beasts or Speedroids
Rarity - Gem-Knights (Agreed)
Applejack - Sylvans

So there you have it. Those are the decks I think they would run if the main six were in the yugioh world.

5745757 cool

5745770
I also did research on what some other characters in MLP would play too.

Shining Armor - Noble Knights
Princess Cadance - Crystrons
Trixie - Performages
Daring Do - Artifacts
Ahuizotl - Zoodiacs
Princess Luna - Lunalights
Sweetie Belle - Melodious
Button Mash - Digital Bugs
Gilda - Harpies

How'd you like that?

5747511 Perfect :)

4556067
What about Spike too?

7946732
Probably dragons, natch

7946840
Ok

Wonder how tough he be?