Taunting Roar is a Weapon Art in Derelict. Taunting Roar charges up before roaring at nearby targets, inflicting Slow effect and heavily decreasing defenses.
"Let out a taunting roar, slowing enemies by 50% for 9s based on distance away from you. Enemies also have their Armor and Resistance reduced by 50%."
Acquisition
Taunting Roar can be obtained by heading to Fort Hollow and then entering the [Hollow's Arch] Ruined Outpost. On the top of the tower, you can find the Chest containing its respective Ancient Arts Scroll. (Map Link)