Almost from their inception the Knights of Vasteel had a division of demon hunters that took on the most diabolical jobs. These men and women equipped themselves with righteous weaponry and charged fearlessly into peril. Holy water, blessed by the priests at the Vasteel Cathedral, became a staple in their work and can be acquired by any aspiring demon hunter for a pittance.
When you hit a target with this bolt, holy water is injected into the target dealing an extra 1d8 Radiant damage. The damage increases by 1d8 if the target is an undead or a fiend.
Additionally, the liquid causes the target to glow softly for 1 hour. A creature marked this way has disadvantage on Stealth saving throws, cannot turn invisible and can be seen in magical darkness.