First off, you should snag Lugia from Greevil. Secondly, bring him to the purify chamber. After that, put Lugia anywhere in the shadow spot. Now make sure ALL the rooms have max tempo. All the way till light blue. Completely full. Then when you leave, it will say....... Something strange is happening to the Lugia. Maybe....... Now purify him. He will have psycho boost, hydro pump, earthquake, and featherdance. Don't get rid of featherdance. Keep it. At level 77 it learns Aeroblast. I hoped I cleared your questions!
Almost an 8 year member! beat that