The Ash of War bestows Blood affinity upon an armament and introduces the skill "Blood Tax."

This Blood Oath skill, granted by the Lord of Blood, involves twisting to build power, then unleashing a flurry of thrusts that rob the target of both their blood and their HP.

Usable on armaments capable of thrusting, with colossal weapons excepted.

To obtain these Ashes of War, head north of the cliff road leading to the Mongovin Dynasty.

Descend the ramp from Bliss. When you arrive in the area below, turn right at the stone pillar and enter the cave.

The Battle Ashes can be acquired by eliminating the dung beetles in the cave.