So, basically what I ask is a Pokemon being "foreign" to increase shiny odds for offspring indicated by a distance from their country of origin, or do they have to originate from areas that speak different languages. This goes for gen 9, not previous generations. An example is an Australia origin ditto originates 14,231 km away from north america, but both countries speak the same language. Would this increase the odds of a shiny.
If two Pokémon are bred that both originate from different languages, any Eggs they produce are more likely to be Shiny. From Generation VI onward, the language of origin is marked by an icon on the status screen.
Foreign language Pokémon obtained via in-game trades, such as the Meister's Magikarp, Foppa, and Lt. Surge's Pikachu, Volty, have a different language of origin to the game they were produced in,[3][4] so if bred with a parent caught in the same save file, the Masuda method applies exactly the same as if the in-game trade Pokémon had been caught in a game of a different language.[5]
The save file's language is not relevant to this process—if both Pokémon have the same language of origin, the Masuda method will not apply even if their language of origin differs from the save file.
From Generation III onward, Pokémon track their language of origin, identifying the language of the game they were originally obtained in. From Generation IV onward, if the two Pokémon in the Day Care have different languages of origin, when an Egg is generated, the game will generate extra personality values in an attempt to find one that results in a Shiny Pokémon for the player. This stacks with the Shiny Charm's effect, which works in the same way.
Source
Therefore, you won't get the boost from two Pokemon of the same language marker, even if they originate from games across the world.
A while ago, I also tried setting an American Game to Japanese and trading that Pokemon to an English-American game. The boost was applied; had the language marker and got a shiny in four eggs ;)
