Splinter Weapons
In the far future of sunshine and rainbows, the Dark Eldar mastered a weapon cruel even for this setting. Taking the Shuriken weapon technology of the Eldar but replacing the standard plasti-crystal ammunition block with a crystallized block of potent toxin instead.
The difference between the two weapons is that the projectiles fired from Splinter Weapons lack the size to deal damage on their own; they act as vessels that puncture armor so that the poisons can do their gruesome work. This means that while they are highly effective against even the largest monsters they are unable to damage tanks and reliably penetrate power-armored targets, forcing the necessity of other weapons to deal with armored targets. They leave the target with a face distorted into an agonised grimace like an even more fucked up version of the Joker. It has yet to be decided whether Splinter Weapons of Duke Sliscus' Corsairs; the Sky Serpents, fire conventional Splinter Ammunition or crystallized manly tears wept by their previous foes.
Also, because of the Dark Eldar's need to cause maximum pain in combat, infantry-carried splinter weapons are normally fitted with a number of blades. So basically, their guns are choppy shootas that shoot choppy dakka. Fluff details that the Dark Eldar have running contests to create even more fucked-up toxins to crystallize into ammunition, the better to cause a number of interesting effects on those they gun down. Interestingly, the Dark Eldar do have antitoxins for their own weapons, but most Dark Eldar consider it a point of pride to not use them. It's also quite likely they'd be dead before it could be administered, but whatever.
Splinter Pistol
The standard sidearm of the Dark Eldar and often employed as an off-hand weapon for many warriors who wield two weapons, this pocket-sized weapon does not rate under its larger cousins in any way in the area of sheer lethality.
Splinter Rifle
The most commonly used weapon by the Kabalite Warriors, it is light and accurate enough to fire on the move while still threatening the enemy with a hail of lethally poisoned splinters.
Splinter Pod
Somewhere between the Splinter Rifle and the Shardcarbine, the Splinter Pods mounted under the Skyboards of the Hellions are designed to fire without a conventional trigger and can still deliver a considerable amount of firepower while on the move.
Shardcarbine
Larger than a Splinter Rifle but not by much, the Shardcarbine fires more reliable and faster than its smaller version at the cost of some maximum range. Favored by many experienced warriors, Scourges and other who thrive on causing pain and death.
Splinter Cannon
The biggest version of the weapons, the Splinter Cannon is small enough to be carried by an infantryman and can still release a lethal hail of fire capable of wiping out entire swathes of infantry at the same time. This weapon has two modes of fire: the regular that allows for the user to move and shoot at the same time, or the heavy mode that delivers a higher rate of fire but requires the wearer to brace due to the weapon's increased recoil.