u must get lugia on ur team. then meteor cave will open that is where deoxys lives. i
suggest bringing 20 luminous orbs if you have that many because there are only 20 floors,
and there are ghost deoxys on every floor except floor 20. that is where the real one is.
you must defeat one ghost deoxys on every other floor to advance. thats what the luminous
orbs r for. you can find the deoxys and then when you defeat it, you can see the exit.
Also, use a pokemon that is lvl 100. that way, with a friend bow, deoxys might join you. I
got it on my first try.

lugia on ur team