Many legendary Fakemon in my region, Natore, have the Light-type. Here, I have outlined its weaknesses and resistances.
Light-type Pokemon take 2x damage from: Dark, Grass
- 0.5x damage from: Steel, Ghost, Fairy, Rock
- No damage from: Fire
Light-type moves inflict 2x damage on: Dark, Ghost, Steel
- 0.5x damage on: Ice
- No damage on: Grass
The way I reasoned the match-ups:
- Grass absorbs light as energy, so it takes no damage from the Light-type.
- Ice crystals refract light, so it resists the Light-type.
- Light drives away ghosts.
- Darkness and light are opposing forces, so they are super-effective against each other.