>>32891996Aside from hacking, fucking nope. The way Mirage Island works is that the first time you boot the game per day it generates a random two byte integer that's stored for the rest of the day when you save. This number is checked against the last two bytes of the personality value of every Pokemon in your party, and if the numbers match, Mirage Island appears. You don't have to talk to the old man in Pacifidlog Town to make it appear, but it's faster.
So because of this if you only had one Pokemon in your party you would have a 1/65536 chance of finding it. If you fill your entire PC with random shitmons caught, each with a different personality value, you'd still have only a 1/156 chance of it appearing, per day. And that's only if you check with all 420 possible Pokemon you can store, and you can't run or use your bike in Pacifidlog town while you're at it. Doing this method takes at least two hours.
The other method is to take a full party and save in front of the old man and let the clock roll over, then start checking and resetting. Because you're not saving, the game treats each boot as the first time you're starting the game that day, and generates a new Mirage Island number. This lets you check enormously quickly, but there is the chance you'll miss it if you're not paying attention, and the probability of this succeeding is still only 1/10923.
I did this about two years ago for four fucking months straight before I gave up. Welcome to hell.