Blade of Blood

Red blood erupts along the weapon's blade, bludgeon, or point. The blood drips to spatter in thick, viscous drops upon the ground. This spell infuses the weapon touched with Necrotic energy. The next time this weapon strikes a living creature, blade of blood discharges. The spell deals an extra 1d8 points of damage against the target of the attack.

You can voluntarily take 5 hit points of damage to empower the weapon to deal an extra 2d8 points of damage (for a total of 3d8 points of extra damage).

The weapon loses this property if its wielder drops it or otherwise loses contact with it.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.