(What if Trem's weapons were real? How would they work? How could their function be explained? I'll give it a try.)
The Blaster:
The blaster emits a weak plasmaburst that moves through the air by attaching itself from one molecule to the other. Because of the ignition of aeral oxygen molecules in the first place, this weapon is self recharging, making it an ideal backup weapon, altough it is relatively weak.
The Rifle:
This is a more oldfashioned assault rifle loosely based on the later versions of the famous AK-47. Being of this ancestry, it fires rapidly in any medium and does never jam.
The Painsaw:
The painsaw is related to the blaster for it uses the same self recharging effect, but the plasma does not leave the weapon but is kept on its front end. The cycles of charging and recharging cause a humming sound that gives the weapon some similarity to chainsaws, giving it its name.
The plasma not having to move through air without a supporting surface, it can be concentrated much higher, making the painsaw maybe the most powerful self recharging weapon possible.
The Shotgun:
The shotgun is an old fashioned but very effective weapon using buckshot projectiles. Shots having a dispersing effect, it is extremely effective on short ranges, but does not much damage on a longer range.
The Laser Gun:
In contrast to the other energy weapons of the arsenal, this one does not use plasma, but a laser beam. Altough lasers cannot deliver that much energy to the target like plasma based weapons can, the beam has one major advantage: It is fast as light, giving the wielder the advantage of being able to hit anything in his sight instantly. In combination with a jetpack, this weapon is the ultimate support for any fighter on the ground and perfect for hunting down aliens in the end after the last alien structure is gone.
The Mass Driver:
The mass driver is the technical realization of something known to be a moreless theoretical construct, the Gauss Cannon. Gauss cannons accelerate a small amount of mass using oscillating electromagnetic fields in the barrel, causing several single accelerations, each in strength compareable to a single ignition of a projectile in a traditional gun, so you fire the same mass with a much higher velocity. Following the physical law of cinetical energy increasing by the square of speed, any mass driven that way is highly penetreable. Altough the mass driver uses depleted uranium bullets for projectiles, it is considered to be an energy weapon because of the high amount of energy it uses and because its bullets are recharged from the still slightly radioactive byproducts of a reactor or repeater.
The Chain Gun:
The chain gun is a Gatlin gun modified for single man operation. Being so, it is not belt fed, but uses an internal magazine, limiting the number of rounds to 300. Also, the gun is pretty heavy, making it uneasy to wield, the recoil of its powerful firing mechanism literally shaking the wielder unless crouching or wearing a battlesuit the weapon can be mounted on.
In spite of all this, the chain gun has enormous firepower and is a serious threat to even the biggest aliens and the only means for an unarmoured human fighter to effectively take down a tyrant.
The Pulse Rifle:
The pulse rifle is the ultimate big brother of the blaster. It uses plasma too, but at the highest concentration that is technically possible, making it a very powerful weapon. Having bursts that are immensely bigger and also get a physcial impulse to move fast in air - giving the pulse rifle its name - the pulse rifle cannot be made self rechargeable. It uses a primary battery to deliver power to its bursts, which reloads from a secondary battery, serving as ammo pack. Battery voltage and therefor capacity can be increased using an additional battery pack.
The Flame Thrower:
This one earned its nickname "bugspray" due to its excellent capability of getting rid of hoards of small aliens, namely dretches and basilisks. It is an oldfashioned flame thrower, igniting an inflammable liquid spray. Altough this weapon is a serious threat to most aliens opposing it, it is also one to its wielder, who can easily damage himself when moving forward while pulling the trigger or standing too close to walls reflecting the clowds of burning spray back to himself.
The Lucifer Cannon:
Now to the most extraordinary and also most powerful weapon, the famous and infamous Lucifer Cannon, a mixture of plasma and electric charge weapon. The details of this technology being kept secret, this weapon has slowly moving bursts which can be charged, delivering an amount of destruction that can instantly kill any single alien when hit directly - except a tyrant - and causes damage even nearby its point of impact by its fallout. The power of a burst is depending on how long the burst is being charged, but if overloaded, the internal barriers of the weapon fail and the energy burst breaks through to the wielder, causing significant damage.
