This guide shows how to find a Sharran Lookout for Shadowheart quest – Daughter of Darkness in Baldur’s Gate 3.
The Sharran lookout is located on the east side of the village, near the Requisitioned Barn, when you first arrive in Rivington in Act 3.
The lookout’s name is Ferg Drogher, but he won’t communicate with you unless you do.
When Shadowheart is in your party and you speak to him, he will point you in the direction of the cloister and you can advance in the Daughter of Darkness quest. He revealed that the cloister is hidden in a place called the House of Grief, in the Lower City of Baldur’s Gate.