Nature reference
Calm Nature Pokémon: +Sp. Def, −Attack
Calm raises Sp. Def by 10% and lowers Attack by 10%. HP and the other stats are unchanged.
Increases+Sp. Def
Decreases−Attack
When does Calm fit?
Consider Calm for Pokémon built to take special hits. It fits best when physical damage is not part of the plan.
The right choice depends on the Pokémon’s moves, role and battle format. A nature does not change types, abilities or move availability.
Calm mint and flavors
A Calm Mint applies +Sp. Def and −Attack stat effects in games that support mints. A mint does not change the Pokémon’s original nature, its flavor preferences, or the nature it passes through breeding.
A Pokémon whose original nature is Calm likes Bitter flavors and dislikes Spicy flavors.