I would like to see a Light-type added to the type chart.
Attack-wise, it would be strong against Dark, Ghost, and Fairy-type Pokémon. It would be weak against Water, Ice, and Steel-type Pokémon, and would not affect Grass-type Pokémon.
Defensively, it would be strong against Dark, Ghost, and Fairy-type attacks. It would be weak to Psychic, Steel, and Grass-type attacks.
Attack-wise, it would be strong against Dark, Ghost, and Fairy-type Pokémon. It would be weak against Water, Ice, and Steel-type Pokémon, and would not affect Grass-type Pokémon.
Defensively, it would be strong against Dark, Ghost, and Fairy-type attacks. It would be weak to Psychic, Steel, and Grass-type attacks.