I'm at work for 4 more hours. When i get home i'll be able to help out all those that didnt get help yet. I'll send you a message with details.
Dont forget, for this to work, you need to join my game. I'll start the fight after you join, and then you have to come into the game while the fight is active and going. So i have to start the fight before you hit PLAY on the options. I'm going to start the fight when you join so it should be fine to just go ahead and load up and jump into the game as normal. So after you hit play and are spawned into the game, i should be mid fight.
Stay up in the bar until i kill him. After i kill him, I'll kill myself. Then after respawning, i'll go back down and fight him again. After i kill him the second time, you should be fixed and can leave the game to try it out on your own and confirm if it worked or not.
Tried this with one of my characters that hadn't even accepted the PryoPete Invincible mission yet (was really hoping to NOT take an 8th character through 3 campaign's) & it unlocked my three other characters that were locked.
Thanks for finding this out Akantra (I keep wanting to pronounce your name as "Akantor", boss wyvern from Monster Hunter series). Just wanted some Seraph grenades & this allowed me to do so. :) --- red_ghost from Monster Hunter / Phantasy Star Universe PSN = rghost1228