Question: what do mints do in pokemon sword and shield?
Answer: While these mints do change the effects of your Pokémon's nature, they don't actually change the nature of your Pokémon so even if you change an Adamant Pokémon with a Timid Mint, despite having the stats of a Timid Pokémon, it still has the Adamant Nature which is what will be displayed and what is used for breeding ...