Valkyrie Profile 2: Silmeria Cheats (PlayStation 2)

Beat the game. Then when entering battle, hold down L2.

You must save at the last save point.

While in Lezard Valeth, leave to the world map and head for the Seraphic Gate. Alicia at
L60 would be a good idea. Defeat the gate guard and go through 3 scenes to fight Celeste. 

Upon beating him you get the wand and as an added bonus, you get Leone and Dylan back.
But they are at a very low level. After finishing your task I suggest you leave the the
purple shining mirror and save.

You must hold down L1 when you enter a battle.