Anyway, I'll be going over every Alien in the series, and offer some of my own thoughts and theories on them. I'm aware of how lame this is, by the way. When writing this I realized how long even a post on one faction would get, so I have decided to split the topic into at least 2 posts if not 3 (likely a Falkok post and a Misc post including Grubs and Reakhohshas).
Usurpation Forces:
Faction Lore:
Spoiler: Show More
Not much is truly known about the Usurpation Forces, although that isn't surprising.
The Usurpation Forces are a hostile alien force who are invading Earth via a portal that directly links Earth to their homeworld. Judging by their name, they "Usurp" technology and planets, or at least, are attempting to. They are willing to use human weapons, vehicles, and machinery in their conquest of Earth, and such examples include the use of Civil Security weapons like Lite Railguns, vehicles like the Hound Walker, and machines like Drones and potentially Corvettes. These aliens use swarm tactics and focus on a quantity over quality mindset, for the most part, sending in countless Minors and Majors as cannon fodder.
Misc:
Some reasoning for why Usurpers use human weapons comes from the fact that Eric ran out of time to give them more unique weaponry. He gave a lore reasoning that some Usurper weapons are not "well-adapted" for Earth's climate. I think this lore is outdated now that we have more Usurpation weapons, and potentially more in PB2.5.
The Usurpation Forces are a hostile alien force who are invading Earth via a portal that directly links Earth to their homeworld. Judging by their name, they "Usurp" technology and planets, or at least, are attempting to. They are willing to use human weapons, vehicles, and machinery in their conquest of Earth, and such examples include the use of Civil Security weapons like Lite Railguns, vehicles like the Hound Walker, and machines like Drones and potentially Corvettes. These aliens use swarm tactics and focus on a quantity over quality mindset, for the most part, sending in countless Minors and Majors as cannon fodder.
Misc:
Some reasoning for why Usurpers use human weapons comes from the fact that Eric ran out of time to give them more unique weaponry. He gave a lore reasoning that some Usurper weapons are not "well-adapted" for Earth's climate. I think this lore is outdated now that we have more Usurpation weapons, and potentially more in PB2.5.
Units:
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The Usurpations field a decent variety of units, all of which use swarm tactics.
Minor: The most basic soldier of the Usurpation forces, likely used as cannon fodder and are almost certainly more common than they appear in the campaign. They tend to use light weaponry and come in vast numbers.
Major: The backbone of the Usurpation forces, the Major features better armor and uses a greater variety of weapons.
Advanced: A unique rank, Advanced Soldiers have their own unique weaponry and seem to have a higher rank than both Minor and Major soldiers.
Destroyer: Destroyers function less like commanders and more like heavily armored soldiers, often coming in similarly large hordes like every other rank. Still, it is likely they have authority over all other ranks and lead them into battle. They use both alien weapons as well as the heaviest human weapons captured.
Ranger (non-canon): Higher ranked than Minor and Major troops but just below Advanced, Rangers use both exotic weapons like the Acid Grenade Launcher as well as more traditional weapons. Most carry jetpacks, allowing them to launch aerial assaults with ease.
Misc: Eric's representation of the ranks in the campaign is certainly odd as it is based around "health" - any Minor with a certain amount of health becomes a major, and majors become destroyers at a certain amount of health as well. Advanced soldiers are kind of just their own thing. It is odd because despite being seemingly higher ranked than majors, they show up before majors, and we also never see minor and major soldiers fighting alongside each other. Destroyers are also super isolated for some reason. Overall I disagree with how usurpers are shown in the campaign and it would be nice to see all 4/5 units mixed together.
Minor: The most basic soldier of the Usurpation forces, likely used as cannon fodder and are almost certainly more common than they appear in the campaign. They tend to use light weaponry and come in vast numbers.
Major: The backbone of the Usurpation forces, the Major features better armor and uses a greater variety of weapons.
Advanced: A unique rank, Advanced Soldiers have their own unique weaponry and seem to have a higher rank than both Minor and Major soldiers.
Destroyer: Destroyers function less like commanders and more like heavily armored soldiers, often coming in similarly large hordes like every other rank. Still, it is likely they have authority over all other ranks and lead them into battle. They use both alien weapons as well as the heaviest human weapons captured.
Ranger (non-canon): Higher ranked than Minor and Major troops but just below Advanced, Rangers use both exotic weapons like the Acid Grenade Launcher as well as more traditional weapons. Most carry jetpacks, allowing them to launch aerial assaults with ease.
Misc: Eric's representation of the ranks in the campaign is certainly odd as it is based around "health" - any Minor with a certain amount of health becomes a major, and majors become destroyers at a certain amount of health as well. Advanced soldiers are kind of just their own thing. It is odd because despite being seemingly higher ranked than majors, they show up before majors, and we also never see minor and major soldiers fighting alongside each other. Destroyers are also super isolated for some reason. Overall I disagree with how usurpers are shown in the campaign and it would be nice to see all 4/5 units mixed together.
Weapons:
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Usurpation weapons are currently canonically limited to the Alien Pistol, Alien Rifle, and Alien Shotgun, though this is very likely to change, according to Eric. Lore on any weapon is pure speculation/theory. If you only want canonical lore, don't read this section.
Alien Pistol (rails): A weak rail-based weapon typically carried by Minor Soldiers. Cheap, recoilless, and easy to manufacture, it is an easy fit for the weaker and less well-equipped Minors but is rarely equipped by other ranks as an alternative to the Projectile pistol.
Alien Pistol (Projectile, to return in PB2.5): A projectile energy pistol that fires two rounds at once. Dealing more damage than the Rail pistol, the Projectile variant is favored by Majors, Rangers, and Destroyers as a backup weapon, who are better able to handle its recoil.
Alien Rifle: Standard energy weapon with highly piercing rounds, decent damage, and a slow rate of fire. Used by all ranks minus Advanced, the Alien Rifle is favored for its accurate fire and ability to place multiple shots in the same spot with ease. The weapon features a visor-link aiming system - the weapon can link with a battlesuit visor, providing varying and adjustable magnification - which removes the need for a physical scope or aiming sight.
Alien Shotgun: The standard weapon for Advanced soldiers, this weapon is unique to both the rank and in function. It is quite unlike a regular shotgun, instead functioning more like a two barreled rifle. The Alien Shotgun lacks the visor-link of the Alien Rifle, requiring users to manually aim - but Advanced soldiers are more than capable of doing so.
Alien Sniper Rifle: The Alien Sniper Rifle is used by Rangers, Destroyers, and rarely Majors, due to the lack of any dedicated "sniper" unit in the Usurpation Forces. The Alien Sniper Rifle is a rail-based weapon used for long-range engagements and can deliver its rounds almost instantly from great range, making it a very deadly weapon. An uncommon sight owing to its expensive nature, it is often supplemented in combat with the human-made Heavy Railgun due to their similar traits, and may even be potentially inspired by human railgun weaponry, due to its only recent appearance.
Alien Acid Grenade Launcher: Lobbing highly acidic and adhesive "pellets", this war crime of a weapon - well, if Usurpations knew what a war crime was - launches an acidic gas mixture contained in a pellet of unknown make and composition. Instead of detonating a grenade-like a traditional explosive launcher, the Acid Grenade Launcher uses these pellets to cause horrific proximity damage by releasing the acidic gas within the pellet. Used primarily by Rangers, who are more than capable of using these Launchers to great effect against grouped infantry. A rare sight, and often supplemented by human grenade launchers or rocket launchers for their more long-range and anti-vehicle capabilities.
Alien Plasma SMG: One of the few rapid-fire weapons in the Usurpation arsenal, it is used by all ranks. Firing explosive plasma rounds at a high rate, the Plasma SMG retains a small size despite its potential firepower, and despite often being a sidearm, it can also be found being used as a primary weapon.
Alien Laser Rifle: A unique laser-based weapon used by every rank besides Minors. The Laser Rifle fires a high energy laser beam that quickly burns through the battery of the weapon, requiring fairly frequent reloads. As the invasion has continued, more Laser Rifles have been seen, seemingly replacing the Alien Rifle in service.
Alien Rail Shotgun: A proper shotgun-like weapon, the Rail shotgun is used for close combat, where its rail projectiles are unparalleled. It is suspected to be a heavy modification of the Alien Rifle. Used by Majors, Rangers, and Destroyers as a close-quarters counterpart to human weapons. It is a recent development and is just one example of the Usurpations adapting to human weaponry.
Alien Pistol (rails): A weak rail-based weapon typically carried by Minor Soldiers. Cheap, recoilless, and easy to manufacture, it is an easy fit for the weaker and less well-equipped Minors but is rarely equipped by other ranks as an alternative to the Projectile pistol.
Alien Pistol (Projectile, to return in PB2.5): A projectile energy pistol that fires two rounds at once. Dealing more damage than the Rail pistol, the Projectile variant is favored by Majors, Rangers, and Destroyers as a backup weapon, who are better able to handle its recoil.
Alien Rifle: Standard energy weapon with highly piercing rounds, decent damage, and a slow rate of fire. Used by all ranks minus Advanced, the Alien Rifle is favored for its accurate fire and ability to place multiple shots in the same spot with ease. The weapon features a visor-link aiming system - the weapon can link with a battlesuit visor, providing varying and adjustable magnification - which removes the need for a physical scope or aiming sight.
Alien Shotgun: The standard weapon for Advanced soldiers, this weapon is unique to both the rank and in function. It is quite unlike a regular shotgun, instead functioning more like a two barreled rifle. The Alien Shotgun lacks the visor-link of the Alien Rifle, requiring users to manually aim - but Advanced soldiers are more than capable of doing so.
Alien Sniper Rifle: The Alien Sniper Rifle is used by Rangers, Destroyers, and rarely Majors, due to the lack of any dedicated "sniper" unit in the Usurpation Forces. The Alien Sniper Rifle is a rail-based weapon used for long-range engagements and can deliver its rounds almost instantly from great range, making it a very deadly weapon. An uncommon sight owing to its expensive nature, it is often supplemented in combat with the human-made Heavy Railgun due to their similar traits, and may even be potentially inspired by human railgun weaponry, due to its only recent appearance.
Alien Acid Grenade Launcher: Lobbing highly acidic and adhesive "pellets", this war crime of a weapon - well, if Usurpations knew what a war crime was - launches an acidic gas mixture contained in a pellet of unknown make and composition. Instead of detonating a grenade-like a traditional explosive launcher, the Acid Grenade Launcher uses these pellets to cause horrific proximity damage by releasing the acidic gas within the pellet. Used primarily by Rangers, who are more than capable of using these Launchers to great effect against grouped infantry. A rare sight, and often supplemented by human grenade launchers or rocket launchers for their more long-range and anti-vehicle capabilities.
Alien Plasma SMG: One of the few rapid-fire weapons in the Usurpation arsenal, it is used by all ranks. Firing explosive plasma rounds at a high rate, the Plasma SMG retains a small size despite its potential firepower, and despite often being a sidearm, it can also be found being used as a primary weapon.
Alien Laser Rifle: A unique laser-based weapon used by every rank besides Minors. The Laser Rifle fires a high energy laser beam that quickly burns through the battery of the weapon, requiring fairly frequent reloads. As the invasion has continued, more Laser Rifles have been seen, seemingly replacing the Alien Rifle in service.
Alien Rail Shotgun: A proper shotgun-like weapon, the Rail shotgun is used for close combat, where its rail projectiles are unparalleled. It is suspected to be a heavy modification of the Alien Rifle. Used by Majors, Rangers, and Destroyers as a close-quarters counterpart to human weapons. It is a recent development and is just one example of the Usurpations adapting to human weaponry.