BAD EGGS
Activate a cheat from the opposite version (Saphire to Ruby and vise virsa) on vol. 1 for Pokemon in PC and a Bad EGG will appear instead of the Pokemon chosen.
It will only eat Pokemon if you have or put a Pokemon in slot 1 of box 1. This might work, if it doesn't. Then it can't be helped.
P.S. Usually the first one obtained will have Pokerus.
If you need more help, we've got more Pokemon Ruby cheats and also check out all of the answers for this game
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