The Epsilon Headquarters (often shortened to Epsilon HQ, Headquarters or HQ), is one of three subfactions of the Epsilon Army.
The Epsilon Headquarters is the defense force of Epsilon’s central hub of operations on the Antarctic continent. As the Epsilon division is dedicated wholly to the protection of Yuri’s ultimate weapon, they work to push the boundaries of military technology further than most would dare think of.
Thanks to extensive research into genetic manipulation, Headquarters’ infantry ranks are filled with mutant super soldiers, culminating in the perfect killing machine, Rahn. But even this is not enough. The Epsilon Headquarters is also the manufacturer of the imposing Aerial Fortress Irkalla, assuring the complete inaccessibility of their frozen stronghold.
The Epsilon Headquarters division was founded sometime between the end of the Third Great War and the Mental Omega War. They have taken over Antarctica for the Epsilon Army and made it their primary base of operations.
By the time Yuri's forces were ready for war, they have already completed the first stealth tank, the Shadow Tank, which was instrumental in causing turmoil within the heart of Russia.
To further cause chaos, they developed a dangerous genevirus and deployed it in a Latin Confederation Headquarters and thus the first genetically mutated humans (including their commando Rahn), were brought into the fold.
When Yuri knew that the Allies were still a threat in his global conquest, he launched an assault deep within London with the Epsilon HQ's prized possession: the Aerial Fortress Irkalla. Though initially successful, it was unable to destroy the unknown flying device that was launched in the final phases of the invasion that halted time and wiped out the entire Epsilon strike force.
As the majority of their technology are still being developed over the early stages of the Mental Omega War, the Epsilon Headquarters had little presence in the war beyond Antarctica. In fact, their tanks were barely finished by the time the Allies had launched the Paradox Engine.
However, once the tanks were completed, the Epsilon Headquarters begin to mobilize in Asia, to investigate Russian and Chinese activities, hamper the research of China and attempt to wipe out the recently discovered facility that was equipped with Chinese experimental technology. Unluckily, the Epsilon HQ outposts in close proximity were vanquished following the detonation of the last MIDAS warhead in the Kashmir facility. After pursuing Yunru that led to the tampering Libra's CAS, a small Epsilon HQ regiment was later dispatched to recover the berserk progeny.
The Epsilon Headquarters assisted in recovering the damaged Psychic Amplifier in Zaire, Africa by means of their Colossi and their commando Rahn. Rahn was later evacuated to Antarctica.
In the final stages of the Mental Omega War, the Epsilon Headquarters engaged in an all-out war with the Allied remnants and the Paradox Engine. However, the outer defenses of Yuri's Antarctican fortress (including 3 Aerial Fortresses Irkalla) were unable to halt the Allied invasion and were destroyed mainly due to the Allies' chrono assaults and time freezing.