Howl of Shabriri

Incantation originating from the maddening Three Fingers. Releases a maddening shriek that causes madness buildup in foes Nearby. This incantation also causes madness buildup in the caster and Makes enemies more likely to target them. It is said that the sickness of the flame of frenzy began with Shabriri, the most reviled man in all history. Dark Souls

The following location: Found in a chest on the second level of the Frenzy-Flaming TowerLandmark. From the Grand Lift of DectusGrace grace site, move South through a mountain path and follow the path. You will come upon a small incline going towards a tall stone tower, use the nearby rocks as cover from the flaming orb above the tower as you make your way towards it. Take a left to climb onto a set of rocks, to your left will be the tower with some small rats and a large rat at the base. Climb 2 ladders and turn around to see a chest containing the Howl of Shabriri incantation.