Nakata'vho-pattern plasma repeater

The Nakata'vho-pattern rifle, classified by the United Nations Space Command as the Type-51 Directed Energy Rifle/Improved (T51 DER/I), more commonly known as the plasma repeater, is a plasma-based directed-energy weapon used by the Covenant, issued to Sangheili as well as Jiralhanae shock troops.

Design details
The repeater resembles the plasma rifle in shape, though with an elongated mid-section and stock, allowing the repeater to be shouldered more like a traditional rifle as opposed to the (ironically-named) plasma rifle's more submachine gun-like hold. The middle of the weapon features a revolving cylinder which slowly ramps up its rate of fire over time, starting with lower rates and accelerating to an extremely high rate of fire in a short period of time.

Unlike its forebears, the plasma repeater features a manual venting trigger that allows its operator to release thermal builup, dispersing it through shuttered ports on the side of the weapon. This allows the operator more precision and control over the weapon, at the cost of the traditional format which dominated the majority of the Covenant's history.

Development history
The plasma repeater was designed as an improvement over the venerable plasma rifle, as one of many efforts done by Covenant manufacturers in an attempt to improve performance over the plasma rifle. Results were generally mixed, though the plasma repeater proved the most effective in this endeavour. As of late 2552, the weapon was suspected by UNSC officials to be new to the Covenant arsenal or specific to only one of the Covenant's military arms, having only been sighted in the field relatively recently at the time.

Usage
The plasma repeater was mainly used from 2552-onward in limited numbers. Many Sangheili preferred its use over more traditional plasma rifles due to its precision and the controlled it offered.

Operational history
The plasma repeater was predominantly employed by Sangheili and Jiralhanae shock trooper forces during the Fall of Reach, at which time the weapon was relatively new in Covenant service. It would continue to go on to be used by the Covenant's successor states, with Merg Vol's Covenant employing it during the Battle of Draetheus V in 2555 and Jul 'Mdama's Covenant employing it in the battles of Installation 03 and New Phoenix.

Differences from the plasma rifle

 * Each shot of the plasma repeater is .5% of the battery, making a total of 200 shots possible. Each shot from the plasma rifle is .25%, for a total of 400 shots possible.
 * The plasma repeater takes 18 shots to kill a fully shielded Spartan, while only 16 are needed with the plasma rifle.
 * The plasma repeater does the same damage per bolt to both health and shields; the plasma rifle does more damage per bolt against shields, but less against health.
 * The bolts fired from the plasma repeater travel faster than those of the plasma rifle (at 50.00 meters, the repeater's shots take .5 seconds to reach the target, while the plasma rifle's take .6 seconds).
 * The bolts of the plasma repeater have a purple hue, in contrast to the blue hue of those from the plasma rifle.
 * The firing rate of the plasma repeater decreases over time; the plasma rifle's increases.
 * The plasma repeater can be manually vented, either all at once or in several intervals, while the plasma rifle is forced to vent excess heat all at once.
 * The plasma repeater features aim assist for the Elites, but the plasma rifle lacks this.

Trivia

 * Unlike most plasma weapons in the Halo franchise, the plasma repeater actually does the same damage to a player's health as it does to a player's shields.
 * The plasma repeater actually never overheats, building up heat which slows its rate of fire and increases accuracy until it is either vented or runs out of battery. This makes it one of the few battery-operated Covenant weapons to not be burdened with a necessary cool-down.
 * There is an odd event that can be performed on the plasma repeater. In a Custom Game, Firefight or Forge, set Infinite Ammo to "Bottomless Clip", so it never loses fire rate due to overheating. Get a plasma repeater and fire it non-stop. The reticle will bloom far beyond the center of the screen. Once the reticle blooms to a certain point, it will reset itself to the middle of the screen again, repeating the process, but faster. After enough time, the reticle will simply be stuck in the center. Ceasing fire will cause the reticle to follow these steps in reverse. Not overheating gives the weapon one of the fastest fire rates in Halo: Reach.
 * Page 333 of the Halo: Reach official guide incorrectly calls the plasma repeater the T51 DER/1 rather than the T51 DER/I.
 * In Halo: Spartan Assault and Halo: Spartan Strike, the weapon is only used by Elite Minors. When used by the player, it carries a maximum of 200 shots.

List of appearances

 * Halo: First Strike
 * Halo: Reach
 * Halo: Spartan Assault
 * Halo: Spartan Strike
 * Halo: Ground Command
 * Halo Mythos: A Guide to the Story of Halo
 * Halo: Official Spartan Field Manual
 * Halo: Divine Wind
 * Halo Infinite