We'll be going the long way around this, due to character decisions...I really hope depleting that gem didn't call the other wizards -_- If so, we're dead. No two ways around that, even if Sorri was a stock-standard cleric.
My Plan: Trade my three remaining spells to bring Talarin (reason for this stated in the post) back to consciousness. After that, we're waiting until the next morning, when Sorri's spell list repopulates and she can start trading them again. Once that happens she brings back Denkou and hopefully will be able to get Den some buffer HP. Rinse, wipe, repeat.
Now, is this a instanced dungeon or will everything respawn while we're sitting here? : P