I heard if you catch latias/sapphire/ or latios/ruby/ and train them to level 67 then go to mossdeep city and go to the place with a tower go inside and talk to one of the people/do all that way you do the right one/he will say you missed 67 lanuches 2 seconds later you will be on the moon once there look for some stairs go up and you find deoxys. If the guy does not say you missed 67 lauches train your latias or latios to level 77 then try again. But don't if it is true?