Bloodfeeding

Book of Vile Darkness 3.5
By Monte Cook

 

Every time this weapon deals damage to a creature with blood, it gains 1 blood point. When the weapon has 5 blood points, it can deal an additional 1 point of damage at the user’s behest (spending the blood points).
The weapon can store up to 50 blood points, allowing an additional 10 points of damage, usable all at once or divided up over a number of attacks.

Caster Level: 7th; Prerequisites: Craft Magic Arms and Armor, vampiric touch; Market Price: +1 bonus.