find it.
what do you do after you get a mystery gift in emerald?
No.
After you catch Rayquaza, you can go back to the Sky Pillar and there is a portal where Rayquaza used to be. Enter it, and you will enter a room and be able to catch Jirachi.
There is no jirachi's cave.
yes
Cheating
No but you can get one from the preview disc for Pokemon colosseum and only from that unless you cheat.
In outer space after getting 5 (five) stars on your trainer card.
you need Pokemon channel for gamecube and you get Jirachi as a bonus.
A shiny Jirachi can be very rarely obtained from using the Pokemon Colosseum bonus disc repeatedly to find Shiny Jirachi. Once it is obtained, you can migrate it from Pokemon Ruby, Sapphire, or Emerald to the Pal Park.
yes with an event.