Deoxys is only available through Pokemon events.
fly to vailstone, then go to the metiors on the right side of the city, go up to them all and press A, then deyoxys level 45 will appear.(i have a shiney deyoxys level 100 :))
I heard it will appear near Meteors in Veilstone after a certain part in the game
You get Deoxys through event or Poke Transfer.
You can't find it in the wild or any special place. You need to transfer it from the older DS Pokemon games or trade for it.
kyogre, rayquaza, latios or latias not sure which 1, jirachi and deyoxys but theyre really hard to get
Pokemon ruby's version IS Pokemon ruby.
Pokemon Ruby has Pokemon that Pokemon Sapphire does not and Pokemon Sapphire has Pokemon that Pokemon Ruby does not.
ruby
Deyoxys is only available through a Nintendo Event (Not going on any more) Or you can use a Gameshark to get one.
All The Shiney Pokemon You Can Get In Pokemon Ruby Are All The Pokemon You Can Get in Ruby Any Pokemon Can Be Shiney Even Starters and Legendaries. So There Are 200 Shiney Pokemon You Can Get In Pokemon Ruby.
You can trade from Pokemon Ruby to another Pokemon Ruby using a link cable.