MJOLNIR Powered Assault Armor/Sentry

Based off of one of the many Post-War BDUs available, specifically the mainline body armor of the Office of Naval Intelligence Security Division.

The MJOLNIR Powered Assault Armor/Sentry is a variant of the MJOLNIR Powered Assault Armor [GEN2], and is utilized specifically by augmented personnel of the Office of Naval Intelligence's Security, Black Operations, and Covert Operations Divisions. The armor itself is adapted from the heavy armor utilized by non-augmented personnel, which in turn was adapted from the UNSC Marine Corps' Post-War heavy infantry armor.

Overview
The MJOLNIR/Sentry variant was designed and manufactured by Cascade Stronghold Technologies, and tested at, on. It was adapted from the modified Marine heavy infantry BDU used by ONI security personnel. Its purpose was to be issued to augmented members of the various operations groups within the Office of Naval Intelligence, who would be assigned to protect highly important installations and facilities, as well as carry out operations normal Security Division personnel could not do with similar numbers. Despite all other MJOLNIR variants being available for use by these ONI personnel, the Sentry variant is the most common used. Even though in most depictions the armor is a flat black, ONI Spartans are allowed to paint their armor whatever color they like, even using those not available to Spartan Branch Spartans.

Its design is aesthetically, nearly the same as the armor it is derived from, with the helmet, shoulder pads, torso armor, and forearms based directly off of the BDU variant. The legs however, had to be designed from scratch but do manage to resemble the legs of the original armor, with built-in storage units on the legs. Additionally, the armor is now made out of Titanium-A, instead of a specially designed composite material, which, while making the armor heavier, offers more protection than the original armor. It also adds a slightly more efficient version of the standard MJOLNIR reactor, the result of ONI research projects.

While the majority of MJOLNIR variants utilize starship-grade Titanium-A composite alloy, Sentry-class armor is made from an even more durable form of Titanium, developed after the war by the Office of Naval Intelligence. This new alloy has a higher temperature resistance than normal Titanium-A, offering better protection against the plasma weaponry used by Covenant forces. It's also sturdier than normal MJOLNIR armor, as it takes more fire from small arms to compromise the integrity of the armor and user inside. The internal software is also a slightly more advanced version of that which is available to Spartan Branch Spartans, allowing ONI Spartans to better preform their high-risk missions.

History
Designed in 2554, the Sentry variant was created in response to the creation of the Spartan Branch, which severely reduced the number of Spartan personnel available to the Office of Naval Intelligence. The lack of Spartans available to ONI left it with in a state unable to carry out many operations it could in the past. Commander-in-Chief Margaret Parangosky approved the augmentation of numerous members of ONI's Security Division, along with the creation of the Sentry variant for their use only. As a result, Sentry armor only sees use within ONI Security, Black Operations, and Covert Operations Divisions. Over a hundred suits are located onboard the ONI Stealth Cruiser, UNSC Vegas, used by the substantial Spartan deployment garrisoned onboard.

After development, the prototype suits were transferred to a facility on the colony of Recea, an Inner Colony that survived the war. On route to the facility after landing on the planet, Admiral Margaret Parangosky, along with attached Cascade Stronghold Technologies technicians and the volunteers, were informed of an attack on the facility by United Rebel Front forces. It was during this that when Parangosky ordered the volunteers to don the suits, a Cascade Stronghold Technologies technician stated that the suits hadn't been tested and might be dangerous. Parangosky was reported to have responded with, "To Hell with safety, we've got security to worry about."

After managing to evade the patrolling rebel forces who were trying to find anything of value to loot, Fireteam Charlie-12 reached the underground portion of the facility where the suits were being held and retrieved them. After equipping their new armor, the team successfully eliminated most of the rebels in the area, and forced the remainder to surrender. The information gained from the captured rebels allowed for a series of successful strikes against insurgent targets in the following months. After the Insurrectionists had been dealt with, Admiral Parangosky was so satisfied that she ordered mass production of the armor on the spot, effective immedeintly.

The first recorded use of the suit after production was green lighted was on November 27, 2554, on the frontier colony of New Albstadt, where three Fireteams of ONI Black Operations assassinated and captured High Value Targets of the growing Insurrectionist movement, the New Albstadt Liberation Party. The operation was a success, with the majority of the group's leaders either being killed or captured by the Spartans. Another successful use of the armor came in January 3, 2555, with the Raid on 'Trevas Keep, on the world of Miraculous Devotion. The Keep was suspected of delivering arms to Insurrectionists and Covenant remnant groups. The mission led to the deaths of most of the Elders, ten percent of the Keep's warriors, and the disappearance of the Kaidon, who was later discovered to have joined with Jul 'Mdama's Covenant Remnant, along with the discovery of several storage crates filled with weapons. The success of the raids on New Albstadt and 'Trevas Keep cemented this armor's use within the Office of Naval Intelligence.

On March 14, 2555, a Covenant Remnant came out of Slipspace by ONI Station Delta-39, a research and development station in orbit around the Frontier Colony of New Frazão, which housed the prototypes of the new MJOLNIR Powered Assault Armor/Penetrator, which was a few weeks away from being tested. ONI Fireteam Foxtrot-14 was onboard the station after running anti-insurgency operations on the world below, and were the first to respond to the Covenant boarding parties. Foxtrot-14 managed to not only hold off the Covenant until the prototypes were evacuated, but also managed to bring the station's sole online, which disabled the cruiser and forced it to withdraw, where it was then destroyed by the newly arrived planetary defensive picket.

The armor's service record was stained on March 15, 2555, during a disastrous mission to the Sangheili colony of Impetuous Belief, where ONI Fireteam Hotel-26 was assigned to ambush a Sangheili envoy of 'Tuyok Keep meant to meet with representatives of the Covenant Remnant to discuss a possible alliance. The team was given the secondary assignment of assassinating the Remnant's leader on the world; the Kaidon of 'Trevas Keep, the very same one who had escaped months ago. The team managed to locate and eliminate the envoy long before they reached the meeting point, however; ONI had far underestimated the resources and manpower 'Tuyok Keep had with them, and the team suffered a casualty. Things were complicated more when the, the UNSC Kem Bennett, disobeyed orders and withdrew after the arrival of two CRS-class light cruisers and an , eliminating any hope of evacuation for the now stranded team. Once the team arrived at the meeting point, they found it to be swarming with Covenant infantry and light vehicles, which quickly spotted the team, forcing them into a massive firefight.

The team managed to locate the Kaidon and cornered him, however; they were not prepared when he lashed out with his Energy Sword, killing one member, and wounding another. The surviving members, Cate Fairbairn and a wounded Pavli Baris, were taken prisoner to be interrogated. Baris would later succumb to his wounds while in captivity on March 17, 2555. Soon, a rescue mission was attempted, this time with the assistance of three Fireteams, and the support of six frigates led by a cruiser. The mission was a success, with Fairbairn being rescued, the bodies of the deceased were recovered, the Covenant Remnant vessels were destroyed, and all remaining Covenant Remnant forces were killed, including the Kaidon. The mission, while in the end a success, was a massive failure when compared to the results of other similar operations.