Source: Tasha's Cauldron of Everything

Your exposure to the Shadowfell's magic has changed you, granting you the following benefits:

• Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20.

• You learn the Invisibility spell and one 1st-level spell of your choice. The 1st-level spell must be from the Illusion or Necromancy school of magic. You can cast each of these spells without expending a spell slot. Once you cast either of these spells in this way, you can't cast that spell in this way again until you finish a long rest. You can also cast these spells using spell slots you have of the appropriate level. The spells' spellcasting ability is the ability increased by this feat.