On the first floor of Venus Lighthouse (the room with the Psynergy Stone in the middle), save the game and turn of the power(NO soft resets!!), then turn it back on and load the game.
NOW YOU MUST FIRST GET THE PSYNERGY STONE. The first fight you'll encounter is Fenrir+Ice Gargoyle. Make sure you attack in this order: Ivan, Isaac, Mia, Garet(you can change this with djinns if it isn't right), but make sure Garet is still fast enough to attack before the Fenrir.
The Ice Gargoyle should die first.
ROUND ONE:
Ivan - Tornado
Isaac - Clay Spire
Mia - Ice Horn
Garet - Flare Wall
ROUND TWO:
Ivan - Defend
Isaac - Defend
Mia - Wish(just normal wish)
Garet - Unleash Torch on the fenrir
Congratulations!! You've got the Kikuichimonji! It's a Light Blade, so equip it on Ivan, and it unleashes Asura most of the time.
You can do this as many times as you want and the Kikuichimonji is worth a lot of money($$$).