She automatically offers to join after you complete the post-main game missions including the final boss. She can be found at the end of Sharpedo Bluff.
First, you meet Dark lugia, then go to the destiny cave where Cresselia is. Prepare at least 30 ultra balls. I would recommend you saving before fighting.
Go to 6 gym and head for the boat
In fact, you can.
In Pokémon Ruby, Cresselia cannot be found because it is not in the game's programming data. Cresselia was created for the 4th Generation of games; Pokémon Diamond and Pokémon Pearl which were for the Nintendo DS, Pokémon Ruby is a 3rd Generation game and therefore before the time that Cresselia was created as a Pokémon.
jirachi is on the first route but is very rare i dont know the others though.
NO!
no you do not
Pokemon Ruby Destiny Reign of Legends ,Pokemon Ruby Destiny Rescue Rangers, Pokemon Ruby Destiny Life of Guardians
You can catch Cresselia on Marvelous Bridge, but you need the Lunar Wing, which you get in the Strange House.
you find cresselia on full moon island
no, cresselia can only be caught in gens 4+
In the game Pokemon ruby destiny
sorry, but that is not an actual game, ruby is a game, but i have no idea what ruby destiny is.
You catch Cresselia