The Divinity of judgment, and order. The Man of Stone, He of the High Places, the Far Shepherd. He’s depicted in many different aspects, but his most dominant appearance is as a man seated on a mountain, with both hands extended forward, palms up. Waiting to weigh, balance, and judge. He was by far the most active Divinity out of the six.
Kolkan resembles the God of the Old Testament in some ways, such as forbidding his worshippers to do many things.
Spoilers: In City of Stairs, Shara finds that Kolkan hid in a piece of glass and fused with Jukov. This being returned and threatened to destroy Bulikov, but Shara killed it with the Black Lead.