The
Dark Elf Amulet is an easter egg.
Penumbra's dagger is required for a quest in Verdistis. Talk to Corinna the Summoner, south of the park in Verdistis. During this quest you should find one of the holy items. Another is in the Dark Forest, and the third can not be found until after entering the castle.
VERY BIG SPOILER ON HOLY ITEMS 
