Amulet of the Sentinel (Patreon)

Wondrous item, rare (requires attunement)

This golden amulet of an eye has a large ruby embedded in its center and eight smaller gems around it. The amulet has 8 charges and regains 1d6 + 2 expended charges daily at dawn. While wearing this amulet, you can expend 1 or more of its charges to use one of the following properties:

Alertness. When you roll for initiative, you can use your reaction to expend 1 charge to add your proficiency bonus to the roll.

Protection. When a creature that you can see within 30 feet of you suffers a critical hit, you can use your reaction to expend 2 charges to turn that hit into a normal hit. Any effects triggered by a critical hit are canceled.

Vigilance. When one or more creatures that you can see within 30 feet of you are forced to make a saving throw, you can use your reaction to expend 2 or more charges. For 2 charges, you grant one affected creature of your choice advantage on the saving throw. For each additional charge you expend, you grant one more affected creature of your choice advantage on the saving throw. You make this choice after you see the roll, but before the GM says whether the roll succeeds or fails.

While you're under my watch, you're under my protection. Don't stray, lest you fall victim to the world's chaos.