Magic Items

Armor (shield), very rare (requires attunement)
This tower shield is made of hundreds of interlocking humanoid bones, dipped in a shimmering silver resin. When you are targeted by a spell, the bones vibrate gently and emit deep, ominous chanting in ancient Oman, lasting for 1d6 rounds.
While holding this shield, you have advantage on saving throws against spells and other magical effects, and spell attacks have disadvantage against you.

Very Rare, wonderous item
This book contains intuition and insight exercises, and its words are charged with magic. If you spend 48 hours over a period of 6 days or fewer studying the book's contents and practicing its guidelines, your Wisdom score increases by 2, as does your maximum for that score. The manual then loses its magic, but regains it in a century.