20 pokemons

1 Dewgong (good attacks)
2 Seels (to evolve into Dewgong, good HP)
1 Blastoise (good attacks) 2 Wartortle (good attacks)
2 Squirtle (to evolve into Wartorle)
1 Poliwag (can do a lot of damage but energy waster)
2 Raticate (hyper fang is good against high HP opponents)
2 Rattata (for a quick 20 damage and to evolve into Raticate)
1 Chansey (high HP, for 1 hit K.O.)
1 Pidgey (use as a longlasting gust of wind)
1 Doduo (free retreat cost, use little energy)
1 Stamie (high HP)
1 Staryu (to evolve into Starmie, good attacks)
1 Dragonair (strong)
1 Dratini (to evolve into Dragonair)

10 Trainer cards

2 Bill (to use after pokedex)
1 Potion (help chansey stay longer)
2 Revive (if a good pokemon is knocked out)
1 Plus Power (to make our attacks stronger)
1 Gust of Wind (to get opponent's weaker pokemons out)
2 Pokedex (to organize the deck)
1 Imposter Professor Oak (to make others lose their good hand)

20 water energy, 8 fighting energy, 2 double colourless