Type-66 Directed Energy Weapon

When the Flood began its campaign of infection in the Milky Way galaxy, the Forerunners found themselves woefully unprepared to fight an enemy of any sort on such a massive scale. Much of the early decades were spent simply trying to understand what they were fighting - the idea of a purely biological foe that could oppose the Forerunners themselves, the supreme masters of technological superiority, was utterly alien to them. So many colonies fell as the Forerunners hesitated, but that does not mean they were totally inactive.
Part of this time was spend developing technologies specifically designed to combat this threat. The concept of a military defied Forerunner culture, and they were forced not only to raise a combat-ready military from scratch, but also to train and arm them. Sentinel drones were certainly better suited to the task, but their production was difficult and expensive, and their limited artificial intelligence made them predictable and rigid. To this end, they developed a variety of armaments for personal combat, allowing Forerunner troops to combat the enemy themselves, using tactical and strategic ingenuity to offset their natural disadvantages.
The Type-66 DEW was developed by Forerunner military strategists as a personal defence weapon, firing a highly concentrated beam of superheated hydrogen/deuterium plasma. The extreme temperatures the plasma is heated to, as well as the micron-thin beam, made it the weapon of choice of Forerunner troops against the myriad of forms the Flood would field during ground campaigns. The design would prove a popular and successful one, and would be the basis of the dozens of other simialr weapons fielded, especially those used by the Constructor, Protector and Sentinel variants. By the end of the war, the weapon ahd become one of the most common pieces of equipment ever used by inhabitants of the Milky Way, a common sight in almost all Forerunner military units.
After the activation of the Halo Array, many of these weapons would lie where they fell, covered by sands, sunken into bogs, or left to gather dust in Forerunner structures. A number of them would later be recovered by the early Covenant, and reverse-engineered to produce a number of commonplace Covenant weapons - the Type-25 Directed Energy Rifle, the Type-25 Directed Energy Pistol, the Type-1 Energy Weapon/Sword and the Type-52 Directed Energy Support Weapon being only the most well-known of the benefactors. An even smaller number of them were recovered in servicable condition, and would be kept by a number of high ranking Prophets as personal sidearms and a badge of status, or incorporated into their hover-thrones - the possession of a Forerunner relic would cow even the most straightforward Sangheili or Jiralhanae into submission, but the mere sight of an object that their "Gods" had once touched was often enough to reduce all nearby Covenant to devout prostration. After the Human-Covenant War, the UNSC would recover two of these weapons, and expend a considerable amount of resources attempting to study and reverse-engineer their own versions, a point of contention with their Sangheili allies who saw it as tampering with the holy relics of the Great Ones. None of their attempts matched the performance of the original, but it still leapt human DEW technology ahead by centuries.
==Remarks==
*"It looks unimpressive, does it not? It is hard to believe that one of these could cut through several shielded Phantom dropships with ease. How great must their foe have been, that this was considered merely a basic form of defence?"
*"It kind of looks like an energy sword hilt, and the electromagnetic plasma guidance interface looks like the blade - but it fires like a sentinel beam, and is able to track like a plasma pistol. I think it would be fair to say that this probably served as the basis for almost the entire Covenant arsenal."
*"I remember the Minister of Acquisition kept one with him at all times - during religious sermons, he would produce it and smile at the accompanying wave of bows. I used to think it was a smile of pride - now I think it was contempt."
*"The boys in Temerity have spent ten years trying to make their own version work, and the best they've managed to produce looks downright primitive by comparison. But when you consider that the prototypes have rendered traditional kinetic weaponry obsolete, its still a major breakthrough."