Very Simple. Fill pokedex completley. Beat Elite Four after filling it (dosent matter if youve beaten them already just do it again). Have HO-OH, Lugia, Entei, Raikou, and Suicune and go to the shrine in the forest. Click on it and it will do the same thing, but after that it shines. Your trainer person does the what thing and you battle a level 100 Celebi. Some say you can find Celebi in the same cave as you find red but the level is only 50 then. Be carefull and save before clicking the shrine. Celebi is really strong. All my legendays are level 100 and Celebi keeps beating me before I can catch it. Use a Master Ball by the way. All I had were Ultras when I was almost lucky enough to catch it. Broke out immediatley when it's HP was real low in the red. HP was same with Lugia and I lost it again. If you lose, Celebi has that power to disapear in time thing, it disapears from the game. You have to go back and defeat the Elite Four yet again, and then hope to find Celebi again in the forest. (My sister found it in the forest after deafeating the Elite Four again.) Enjoy. Hope you can catch Celebi (I still havent. The master balls don't work on Celebi instantly, it breaks out of them when the HP is in the green.) Well... Good Luck!
Added by: Lugia_Is_My_Master Jun 16th 2011, ID#5338