Shadowfell Shard
Wondrous item, spellcasting focus, rare (requires attunement by a sorcerer)
- Cost: ⏤
- Weight: 1.0 lbs.
This dull, cold crystal sits heavy and leaden, saturated by the Shadowfell’s despair. As an action, you can attach the shard to a Tiny object (such as a weapon or a piece of jewelry) or detach it. It falls off if your attunement to it ends. You can use the shard as a spellcasting focus while you hold or wear it.
When you use a Metamagic option on a spell while you are holding or wearing the shard, you can momentarily curse one creature targeted by the spell; choose one ability score, and until the end of your next turn, the creature has disadvantage on ability checks and saving throws that use that ability.
Sources
Tasha’s Cauldron of Everything p. 135