Here:
http://starocean.wikia.com/wiki/Opera_Vectra
Upload a save after reaching Cross castle for the first time, or after the Lacour tournament. This must be before clearing Hoffman ruins, and you must not have recruited Ashton.
- Do a Private Action in Cross that involves a three-eyed man leaving Cross Castle.
- Continue, and finish the Lacour Arms Tournament. (Skip this if you already finished the tournament)
- Go to Hilton, don't trigger a Private Action. Enter Hilton normally, and enter the bar there. You will encounter Opera.
- Go to Cross, enter the castle, and talk to the King. Ask him about a three-eyed woman. You'll receive permission to enter the Mountain Palace, as well as 10000 Fol.
- Go to the Mountain Palace. To get there, follow the path to Clik until it diverges towards the mountains.
- Once in the Palace, follow the path on the right, and you will eventually find Opera.
- Go to Arlia and trigger a PA, talk to Opera.
- Go into Shingo forest into the clearing you started the game in as Claude/Rena
- Clear Hoffman Ruins with Opera in Party to fight possessed Ernest.
http://starocean.wikia.com/wiki/Opera_Vectra
Upload a save after reaching Cross castle for the first time, or after the Lacour tournament. This must be before clearing Hoffman ruins, and you must not have recruited Ashton.
- Do a Private Action in Cross that involves a three-eyed man leaving Cross Castle.
- Continue, and finish the Lacour Arms Tournament. (Skip this if you already finished the tournament)
- Go to Hilton, don't trigger a Private Action. Enter Hilton normally, and enter the bar there. You will encounter Opera.
- Go to Cross, enter the castle, and talk to the King. Ask him about a three-eyed woman. You'll receive permission to enter the Mountain Palace, as well as 10000 Fol.
- Go to the Mountain Palace. To get there, follow the path to Clik until it diverges towards the mountains.
- Once in the Palace, follow the path on the right, and you will eventually find Opera.
- Go to Arlia and trigger a PA, talk to Opera.
- Go into Shingo forest into the clearing you started the game in as Claude/Rena
- Clear Hoffman Ruins with Opera in Party to fight possessed Ernest.