with a gameshark or try a better thing an action replay
as of right now its impossible, you need cheats.
by using an action replay
it's from events it was in long time ago no point asking
To get the mystic island on Pokemon Emerald you must acquire the Aurora ticket, Old sea map, or Mystic Ticket from a live Nintendo event. These allow you to travel to Naval rock, Birth and Faraway island to encounter legendary Pokemon.
this action replay code let you buy eon ticket and mystic ticket at a Pokemon mart. cff34abfb51248a9f7e323e217a5cca3c2d1840a9f6b65c1 and the action replay code for old sea map and aurora ticket is cff34abfb51248a98f575f429fecd9741584dfb442758518. Use one code at a time. For example: use the eon and mystic ticket code first. Then, when you have bought the tickets turn the code off and use the old sea map and aurora ticket code.
I don't think so but you have to get either the mystic or aurora ticket to meet Deoxys...
In order to get an Aurora ticket or the Mystic ticket you would have had to participate in one of several worldwide events (which are long over). What I would suggest is either mix records with someone who has one. You can also buy the tickets on places like ebay.
You can get the Mystic and Aurora Ticket from a special Nintendo/Pokemon event such as the ones that happened in 2004, but they have expired and no longer can obtain them this way. You will need to use an Action Replay or GameShark to cheat for the Mystic Ticket.
noooooooooooooooooooooooooooooooooooooo. no
Its not possible to get any other way.
These are event items given out at promotional events. It is also available to people using cheating devices such as a Gameshark.