Unholy surge

Characters who serve gods of murder, strife, and other base deeds craft these weapons of pure evil for themselves and for others who share their foul desires. This weapon functions as an unholy weapon (DMG 226). This is a continuous effect and requires no activation.

In addition, on a successful melee attack with an unholy surge weapon, you can command it to emit a burst of unholy energy, which deals an extra 3d6 points of damage to a good-aligned target. If used against a non-good creature, it deals no additional damage, and that use of the ability is wasted.

This ability is usable a number of times per day equal to 1 + your Cha bonus (if any). Once you activate this property, it can’t be activated by any other creature until the following day.