Have you tried every check open to you? If one is walling you, go check the other checks available to you. That might open up new treasures and new characters/espers that will give you new tools.
Check to see if your bosses can be cheesed somehow. Can you absorb all of its attacks? Will vanish protect you? How about reflect?
Retail therapy - Go shopping. Most shops are available to you at all times, go see if the shops have relics, armor, or weapons that will help get you though.
Learn a few spells - See what spells you have on espers, and go fight a few random battles to learn the spells and see if that helps you get through.
Grind a few levels - Depending on your scaling settings this may just give you more HP as a buffer, or it might let you get ahead of the enemy entirely.
If you are still stuck send the seed and details in a PM to Ravlin