You are prepared to do the skill.
You aim carefully as you toss vial towards Guard.
Vial hits Guard on the head shattering into pieces.
Guard screams in pain as holy water burns its skin.

The voice of Elders echoe in your head, 'EXCELLENT!, You managed to complete
this quite challenging task in three hours. You are a credit to the guild.'
Your glass pendant is suddenly bathed in bright light, dazzling you
completely.

* CONGRATULATIONS! You have completed nun task 'Might of Holy Vials'*

Amulet: Vial pendant with inscription 'Heretic' <red glow>

Well, that was fast-ish, after preparing 100 vials beforehand...