Mario Super Sluggers
The Baby Fan
I put in a Pokemon of each type, and this is a Super Effective battle. Attack a type that is weak against your opponent (Rock attacking Bug for example) and you can take two HP away. The Pokemon can only use moves of that type, and abilities and second typings (like how Heracross is both Bug and Fighting) are not accounted for. Resistance does not matter either.
Miltank (Normal): 20
Electivier (Electric): 20
Froslass (Ice): 20
Weavile (Dark): 20
Breloom (Grass): 20
Toxicroak (Poison): 20
Starmie (Psychic): 20
Gyarados (Flying): 20
Skarmory (Steel): 20
Houndoom (Fire): 20
Gengar (Ghost): 20
Dugtrio (Ground): 20
Heracross (Fighting): 20
Sharpedo (Water): 20
Yanmega (Bug): 20
Rampardos (Rock): 20
Dragonite (Dragon): 20
Miltank (Normal): 20
Electivier (Electric): 20
Froslass (Ice): 20
Weavile (Dark): 20
Breloom (Grass): 20
Toxicroak (Poison): 20
Starmie (Psychic): 20
Gyarados (Flying): 20
Skarmory (Steel): 20
Houndoom (Fire): 20
Gengar (Ghost): 20
Dugtrio (Ground): 20
Heracross (Fighting): 20
Sharpedo (Water): 20
Yanmega (Bug): 20
Rampardos (Rock): 20
Dragonite (Dragon): 20