What Pokemon is the strongest Pokemon in Pokemon Ruby?
The strongest pokemon in pokemon ruby is Rayquaza!!! Rayquaza knows ExtremeSpeed Fly Uproar.
Arceus, the legendary Pokemon, is the strongest Pokemon ever. Search for it on the Pokemon websites pokedex to findout loads more about it. However for ruby, sapphire and emerald which you've classed your question as, rayquaza is the strongest Pokemon and it can be found on the top floor of the cave just east of that floating town. Be warned its level 70. hope that helps