Z-390 incineration cannon

The Weapon/Anti-Materiel Z-390 High-Explosive Munitions Rifle, also known as the incineration cannon, is a Forerunner anti-matériel weapon originally used to combat the Flood.

Overview
The Incineration Cannon was often used to strategically purge infected sites. Prometheans used the Incineration Cannon when assaulting a location believed to contain a Gravemind, or early-forming spore mountains, that were deemed too small for ship weapons but too large for infantry weapons. The Incineration Cannon fires five antimatter-infused streams of concentrated explosive particles, which gather into globular projectiles that oscillate along a straight trajectory and disintegrate targets when landing a killing blow. The projectiles detonate and spread upon impact with a target, ricocheting and bouncing in tall but short arc trajectories. It initially holds five whole charges at a time with one shot per charge. Each charge is automatically "loaded" after firing and cool-down. It has been described as "mixing traits of a rocket launcher, shotgun, and flamethrower."

Design details
The weapon possesses an angular design and a metallic casing. It appears to be held together, at least partly, by energy fields as indicated by its self-assembly process and reloading mechanics. Red highlights can be seen while the weapon is self-assembling and throughout the casing once assembly is complete; these highlights grow brighter when the weapon is fired. The weapon features an integrated optical scope for targeting accuracy.

Variants

 * River of Light: The River of Light was created during the Forerunner-Flood war, which led to many technical advances that ultimately proved fruitless. Upgraded with increased damage, a wider projectile trajectory, 25% increased battery capacity, faster charging speed, and faster heat dissipation, it unleashes long bursts of seven energy blasts if charged up. Available as an Ultra Rare REQ for Level 5 energy in Warzone simulations, the River of Light is also available as a secret weapon in the mission Reunion.
 * Heartseeker: The Heartseeker, carried by Warrior-Servants relentless on the hunt, fires slower-moving but more powerful energy charges with very strong homing behavior, 30% increased range, and a wider blast radius over the standard weapon. It is available in Warzone simulations as a Legendary REQ that costs Level 6 energy.

Changes from Halo 4 to Halo 5: Guardians

 * Power of the weapon is determined by how long the user holds down the trigger, with uncharged shots firing a burst of two projectiles with arcing trajectory and fully charged shots having a similar effect as those of the previous incarnation of the weapon, albeit without any secondary explosions. Keeping the weapon charged will slowly deplete its battery, similar to the Plasma Pistol.
 * Uncharged shot consumes 5% of each shot while fully charged shots mainly can consume up to 25% in total.
 * Single-charge "magazines" have been replaced with a battery meter.
 * Lights on the weapon have switched from red to orange.
 * Time between fully charged shots is shorter.
 * Ammo total reduced from 6 to 4 for full charged shot and increased from 6 to 20 for uncharged shot.

Halo: Spartan Strike

 * Carries a maximum of 8 shots.
 * Inflicts significant splash damage.
 * Can destroy a Wraith or Scorpion Tank in one precision shot.
 * Requires open area for safe use. As with other explosive weapons, splash damage at close range can injure or even kill the player.

List of appearances

 * Halo 4
 * Spartan Ops
 * Halo: Spartan Strike
 * Halo 5: Guardians