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. 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.

River of Light
The River of Light unleashes long bursts of energy blasts if charged up.

Heartseeker
The Heartseeker fires tracking energy charges.

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.
 * Single-charge "magazines" have been replaced with a battery meter.
 * Lights on the weapon have switched from red to orange.

List of appearances

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