Bone Blade

The Bone Blade is a special sword found in a chest on Level 5.5. It can have Magic Crystals socketed into it, though green crystals are the only ones to have an effect.

Whenever the Bone Blade strikes an enemy its edge becomes weaker, alluded to by its item description describing the blade as "...very brittle." It is found with seven slash damage, but will degrade by half a point for every hit until it reaches 3. When socketed with a Green Crystal, its slash damage will quickly raise back to a maximum of 7, draining the Crystal of some power.

Trivia

 * The Bone Blade is exceptionally good against all enemies found in Level 5.5 due to their lack of armour.
 * The Bone Blades use of Green Crystals is similar to the Strange Masks use of Green Crystals, which heals the wearer like the Bone Blade heals its blade.