Resources Preventing Success

I am about ready to finish the Ice Shrine with reversed parties (Busho in the Evil Shrine). Since Busho’s party was given (without my approval)
all the items, Caius' party has virtually no resources other than what is found/bought. The biggest problem is that no TP potions can be purchased anywhere so battle strategy is focused around the minimal use of TP. The Arena is the only place with a store to buy stuff and the selection is dismal. Am I missing something obvious?
Q25 Lift the Sword
EDIT: I just spent the last 45 minutes of my life with the last Mimic left in the Ice Shrine. Save, fight, wait for Hero Potion drop, exit game, repeat from save point. Finally a hero potion dropped.
Q42 Romance Paused
Locked Chest in Ice Shrine Requires “Man of Considerable Magnitude”.

Q25 Lift the Sword
Spoiler: show
EDIT: I just spent the last 45 minutes of my life with the last Mimic left in the Ice Shrine. Save, fight, wait for Hero Potion drop, exit game, repeat from save point. Finally a hero potion dropped.

Q42 Romance Paused
Spoiler: show
Locked Chest in Ice Shrine Requires “Man of Considerable Magnitude”.
Spoiler: show