>>19170565Every day, a random number between 0 and 65535 is generated by the game. If this number matches the last two bytes of the personality value of any of the Pokémon in the party (that is, the remainder when their personality value is divided by 65536), Mirage Island will appear for that day.
>>19170571Same encounter data that every other location in the game has. It's technically not unused since you could hatch an egg there to have a pokemon with the encounter data of Scorched Slab, but you can't encounter anything else there.
