[ASM & Hex] HGSS Everstone in Pokemon Emerald

[Snow_Bunny01]

I'm looking for a way to implement the HGSS Everstone in Pokemon Emerald. It's where if the Everstone is held by either parent in Pokémon Day Care, bred Pokémon have a 50% chance of having the same Nature as the parent holding the Everstone. In Pokémon Emerald, if held by a female Pokémon only or Ditto in Pokémon Day Care, bred Pokémon have a 50% chance of having the same Nature as that parent. So I need to update it. Is there any research on this, or does anyone know how to do this? Thank you.