WAR MASTER-class Mjolnir

The MJOLNIR Powered Assault Armor/War Master is a variant of the MJOLNIR Powered Assault Armor [GEN2] utilized by SPARTAN-IVs. It is Lethbridge Industrial's most popular and most exotic armor system.

Behind the scenes
Based on its skull-like appearance, the War Master helmet seems to be a canonical counterpart to the Haunted helmet from Halo: Reach.

List of appearances

 * Reclaimer Trilogy
 * Halo 4