Kyshaarth's Fang

This dagger's blade is composed of black, bone-like material. Tales suggest the weapon is fashioned from a Voidling's (see Tome of Beasts) tendril barb. When you hit with an attack using this magic weapon, the target takes an extra 2d6 necrotic damage. If you are in dim light or darkness, you regain a number of hit points equal to half the necrotic damage dealt.