Equipping the Giant Sword would require buying a Maiden's Tears, which isn't sold in the shops. In terms of every item in the code including unobtainables:

Return Ring -> Dagger
Water of Life -> Short Sword
Sleeping Bag -> Long Sword
Tent -> Broad Sword
Strength Honey -> Scimitar
Intelligence Honey -> Ice Blade
Endurance Honey -> Undead Blade
Agility Honey -> Fire Blade
HP Honey -> Dragon Blade
MP Honey -> Magic Sword
Herbs -> Lightning Sword
Medicine -> Desiree
Silver Flask -> Crystal Sword
Gold Flask -> Spirit Sword
Maiden's Tears -> Giant Sword
Moon Oil -> Golden Sword
Enchanted Jewel -> Cursed Sword

Also of note, Medicine becomes Desiree. Also also, you can put weapons on your armor and amulet slots too. Lv1 Rooks with a Crystal Sword on armor has 98 defense. On the amulet slot he gets 52 defense, and checking the extended stats in my mod... 15 magic defense and a resistance to undead, medusa, dragon and giants.

I should list the Item IDs on Data Crystal, but I'll put them here.

01 Return Ring
03 Sleeping Bag
04 Tent
05 Strength Honey
06 Intelligence Honey
07 Endurance Honey
08 Agility Honey
09 HP Honey
0A MP Honey
0B Herbs
0C Medicine
0D Silver Flask
0E Gold Flask

OK, I got Rooks the Crystal Sword in Chapter 1. It works! As a note, the glitch puts the item ID at that address. So depending on which item you're buying, you'll set a different value.

I haven't found a way to go forward through memory, otherwise a lot more stuff could be broken into.

That list just keeps track of who's holding what, it doesn't actually affect your stats. On the other hand, what does affect your stats might be reachable with a ton of scrolling.

$1283: Equipped weapons

• Two bytes each, in order of Rooks, Guest 1 and Guest 2.
• item ID / "Equipped by" flag

Modifying this won't put the item in your inventory, but your character will be holding it. Until you equip something else, then it'll vanish. (A side note, this is what gets modified in the final fight to give you the Giant Sword.)

I added some of the game mechanics like run chance and physical accuracy. Let me know if there's something you'd like me to look into, I've been reverse engineering this game for a while.

Ah, just realized I didn't see a notification for this. Sorry for the delay!

I've got a RAM map on Data Crystal; address $13A9 is the first card slot. It's possible to sell certain cards then throw out the corrupted cards, but the game freezes for a bit when selecting it in Cards. And some card combinations make the shop stop responding; could probably put together a complete list, but off the top of my head avoid Fire x2 and Fog x2.

Also it's possible to set your active spirits to Sylph+Dao in Chapter 2 this way, not sure if Change Attr to Earth saves any time. Earth spells are more accurate, though.

Hmm, it won't let me post the link. I'm not a bot, darnit! It's on my YT, same username.

Heya! Wasn't sure if anyone here was aware, but there's a major exploit in this game that can be used for quick money. It's pretty unwieldy and you need the right setup, but maybe it could be used for Fog Cards or honeys more efficiently.

Basically if you Trade for your second+ item but don't have the money, the cursor gets put back wrong. You can scroll up past your first item into out of bounds memory and sell other stuff. This isn't where the game progression or chapter is stored, but you can sell unused memory for like 20,000 GP. You're also setting that address to 7 (Chapter 1) or 15 (Chapter 2+), so casually you could reset your LVL or get Dao in Chapter 2. But that also means if you don't count correctly, you could set your max HP to 7.