The remnant of the ruby taken by Crandulet, which can be channeled through the Sapphire Claw to be imbued by it. Once attuned to the remnant, it has no mass or physical presence. The user can choose to drop the remnant entirely or to return it to the Sapphire Claw.

When attuned to the ruby remnant, the first two times (charges reset after a long rest) you would be knocked unconscious as a result of your hit points being reduced to 0, you instead remain at 1 HP and, as a reaction, may target the enemy that attacked you with a 3rd-level hellish rebuke that has a DC of 15 or your spell save DC, whichever is higher. (Note: the enemy must be within the 60 ft range of hellish rebuke.)

You may not use the ruby remnant if you were already at 1 HP when attacked or if the attack dealt enough damage to instantly kill you (that is, dealing damage equal to your remaining HP + your total HP); however, you may still use the ruby remnant to save you against spells such as disintegrate that would instantly kill you if the spell brings you to 0 HP.

Notes: using the Sapphire Claw