Rance 4:Items

Rare Items
Some non-essential items are rare drops inside Treasure Lumps around certain general areas. There's no tricks currently known for getting them except grinding. The rewards are very good, however.
 * Belief Key: Buster Sword
 * Betrayal Key: Hanny Knife
 * Chernen Powder: The item shop becomes Rance's. Everything costs no gold, and Yocchan becomes Rance's as well (new CG).

Black Sword
In the main tower of Surface Central Area, you can exchange any 3 swords for Black Sword. The attack power of Black Sword will equal half of the sum of 3 swords' attack. Stamina requirement is always 10, and the sword is always dark elemental. Thus, you should use strong but impractical swords (due to stamina cost) to obtain Black Sword.
 * Strongest Black Sword (78 attack; possible at the start of chapter 6): Invincible Sword + Buster Sword + Alice Sword
 * However, obtaining Black Sword at chapter 4 will make the rest of the game much easier. Invincible Sword + Golden Sword + Buster Sword gives 70 attack Black Sword. If you don't have Buster Sword, then just use another Golden Sword for 62 attack Black Sword.