The Guiding Eye

 is a enchanted item in Total War: Warhammer II.

Description
Wrought in black iron with an oval ruby at its centre, the Guiding Eye grants mystical sight to its wearer.

Effects

 * Type: Augment (area)
 * Duration: 18 Seconds
 * Target: Around self, affects allies in range
 * Effect Range: 40m
 * +20% Armour-piercing missile damage

Source
https://twwstats.com/abilities?q=the%20guiding%20&right=2049963969484436867