If you could create an expansion what would it be like?

[Chimchar boy]

If you could create an expansion what would it be like?

Mine: Diamond and Pearl Mystic Heroes

Decks:

Ancient battle (Water)

Pokemon: 20
Mammoswine x1
Piloswine x2
Swinub x4
Kingdra x1
Seadra x2
Horsea x3
Tentacruelx2
Tentacool x3
Delibird x3
Trainers: 15
Mariah's perserverance x2
Potion x2
Speed ball x2
Rival x4
Energy search x3
Poketopia x1
Enegies: 25
Water energy x25

Techno blast (Psychic/normal)

Pokemon
Porygon-Z x1
Porygon2 x2
Porygon x4
Delcatty x1
Skitty x3
Grumpig x3
Spoink x4
Lunatone x3
Trainers
Natalie's success x2
Potion x2
Speed ball x2
Prof. Rowan x4
energy search x2
Poketopia x1
Energies
psychic energy x25


Lv.x:

Dusknoir (psychic)
Roserade (Grass)
Weavile (Dark)


How bout yours?:)