Quick level-up of Jade Fairies
Fairies level up by collecting the little blue energy spheres that enemies rarely drop. Each crystal is worth 50 Experience points and most fairies take 4 spheres per level.
If you're desperate to level them up, go in the southeastern door just inside the first floor of the Brain Lord/Abell ruins and continue through to the dark room with the light switch, the two floating panels, and the sea of electric tiles. One of the blue enemies there (the one closest to the northern wall) will always drop an energy sphere so you can level your fairies up as much as you want.
Hints for Completionists
Since the game only offers 48 item slots to the player, and since there are many items that are rare, scarce, or temporarily obtainable in shops (especially the ones from the Errant Merchant), those hints below will allow you to maximize the empty slots (for you to use with health items) and leave the unnecessary (but rare) items in their treasure chests.
However, remember that you must collect every single treasure in the Ice Castle, because this place is the the only one you can't revisit after defeating the boss.
The Reviving Mirror can be replaced by the Deceased Jade. Level him up in the Abell Ruins. You'll have more "lives" with him than with the mirrors.
Unique/Rare/Scarce Items that must be left inside their treasure chests
- Scrap of Paper - Town of Arcs
- Buckler - Town of Arcs
- Reviving Mirror - Tower of Light, 2nd floor
- Magic Wallet - Tower of Light, secret room on 1st floor
- Long Bow - Tower of Light, 2nd floor
- Chain Mail - Tower of Light, 2nd floor
- Reviving Mirror - Tower of Light, 4th floor
- Banded Mail - Abell Ruins, 2nd floor
- Reviving Mirror - Abell Ruins, 2nd floor
- Reviving Mirror - Abell Ruins, 4th floor
- Lightning Bow - Droogs Cavern, 1st floor
- Rock Breaker - Droogs Cavern, 2nd floor
- Reviving Mirror - Platinum Shrine, 1st floor
- Reviving Mirror - Platinum Shrine, 2nd floor
Unique/Scarce Items that must remain with the player
- Leather Helmet - Starting Item
- Leather Armor - Starting Item
- X-Ray Glasses - Tower of Light, 2nd floor (cannot be sold or discarded)
- Cape - Abell Ruins, 4th floor
- Blackgold Helm - Ice Castle, 1st floor
- Reviving Mirror - Ice Castle, Basement 1
- Reviving Mirror - Ice Castle, Basement 1, too
- Spiked Boots - Ice Castle, Basement 1
- Battle Shield - Ice Castle, Basement 2
- Fire Sword - Ice Castle, Basement 2 (cannot be sold or discarded)
- Heavy Mall - Ice Castle, Basement 1
- Drink - Ice Castle, Basement 4
- Platinum Helmet - Platinum Shrine, 1st floor
- Royal Armor - Platinum Shrine, 3rd floor
- Platinum Sword - Platinum Shrine, 3rd floor
- Drink - Platinum Shrine, 3rd floor
- Great Axe - Platinum Shrine, 4th floor
- Jades[1](13)
- ↑ You can sell your Jades to Meister in Toronto for the half price you bought them, and he'll store them for you. They will keep the same level they had when you rebuy them.