Devastating Avatar Helmet is an epic-quality equipment item that is only available to Heroes and is sold by Requisitions-T2V. Once equipped, it unlocks the Avatar Bombardier head costume style.
Source[]
The Devastating Avatar Helmet is sold by Requisitions-T2V, a vendor found within the Power Core of the Hall of Doom. The item costs $429 and 80x Mark of Conquest.
Vendor item[]
Style unlock[]
Upon equipping the Devastating Avatar Helmet, a character unlocks the Avatar Bombardier head costume style, which can be accessed at any time from the Style Window.