Starlit Mantle

Wondrous item, very rare (requires attunement) Price: 30,000-50,000 gp | high sentimentality

This cloak is a window into a starry night sky and magic seems to bounce off it. While wearing the cloak, you gain a +2 bonus to saving throws against spells.

Paid

While wearing the cloak, you gain a +2 bonus to AC when targeted by spells.

Overpaid

While wearing the cloak, you can use a reaction to share the effects of the cloak with one creature within 5 feet of you.

Source: The Gray Merchant of Asphodel