- “Leveraging classified Forerunner technology acquired from Requiem, this kit was developed for highly experienced S-IV personnel by the Office of Naval Intelligence.”— DLC description
The Mjolnir Powered Assault Armor/FOTUS is a variant of Mjolnir (GEN2) utilized by the SPARTAN-IV's. It is manufactured by 343 Industries and was tested in Kirkland, Washington, URNA and received high movement proficiency ratings for coffee runs on rainy days.
- In Halo 4, the armor could only be obtained by purchasing the Halo 4 Limited Edition Xbox 360 Bundle. The bundle also includes an exclusive Xbox 360 avatar costume version of the armor. In Halo: The Master Chief Collection, the armor can be worn by any player.
- "FOTUS" is an acronym of "Fist of the Unicorns," a musical band comprised of crewmen on the UNSC Pillar of Autumn in 2552.
- The description refers to Washington State being known for its coffee and having the most rainfall of all the United States.