Im not sure about this but I once went underground and found a fossil with one of those tentacle things that Deoxys had but the wall colapsed before i could get it but i think you need a fossil to get Deoxys.
you get an action replay and cheat
i did not catch deoxys without action replay it is really easy with action replay
Unfortunately, you cannot catch Deoxys without the Nintendo Event. This event has been over for a while.
You can't catch Deoxys without having gone to a Nintendo Event (which has been passed for several years now) where you get something that allows you to go to the island where you can catch Deoxys, or without cheating. It's impossible.
No, Deoxys is only in Emerald, and you need to migrate it to can catch it. As for Celebi and Mew, you need a cheat code for them.
you cant without ar
nope
You can't.
You cannot catch Deoxys in Pokémon Sapphire, Deoxys was only available through Nintendo events which are no longer available as of 2014 for Gameboy Advance games.
Cheat to get the aurora ticket then go to birth island to capture deoxys.
To catch Deoxys (without cheating) you have to get the Aurora Ticket from a Nintendo event. You can then go to Birth Island, where you will find Deoxys. there's a cheat code to get to birth islands ! you have to enable the code and then enter any place like a house or poke center or mart... ok the cheat code to birth islands is E5AC0043 E1C4C8F0 (use game shark)
You catch deoxys at birth island.