Dark Shard Amulet

This amulet is fashioned from a single shard of resilient extraplanar material. While you are
wearing it, you gain the following benefits:
•You can use the amulet as a spellcasting focus
for your warlock spells.
•You can try to cast a cantrip that you don't
know - it must be on the warlock spell list and
you must make a DC 10 Int. (Arcana) check. On
a success you cast the spell; else the spell fails and
the action used is wasted. Either way, you can't
use this property again until you f