Unique Forces of Tzeentch
Cultists
1: Crystal Warriors: Tribals from the Crystal Blades homeworld, these warriors of Tibuna are armed with spears tipped with particularly energetic crystals that allow the warriors to fire powerful psychic beams from the tip, or do damage similar to a force weapon if used in close combat, even if they do not themselves have any psychic powers.
2: Crystal Shaman: The Shamans of the Tibuna tribes often make usage of psychic powers that manipulate the crystals that cover their homeworld. Due to this, only the most powerful among them, who have learned how to actually create the crystals of Tibuna in the midst of battle, ever leave Tibuna proper.
Mutants
Creature
1: Crystingers: Scorpions with shells composed entirely of crystal, the Crystinger for the most part attacks like the average tank sized scorpion with armor harder than adamantium across the galaxy, though these ones can fire psychic laser beams from their stingers for ranged combat.
2: Sharpticks: Ticks with psychic crystal integrated into their very blood, they are well known for their habit of latching onto a given target and then exploding with roughly double the power of the standard Imperial krak grenade.
3: Crystal Behemoth: Turtle like creatures the size of an Imperator Titan, with shells entirely composed of crystals. The Crystal Behemoth is notable for regeneration potent enough that even at it's titanic size, one can heal from the loss of a major limb in minutes. Offensively, they are known for a powerful bite and the ability to cast psychic abilities utilizing their own shells as a catalyst. Incidentally, when they bite into a daemon they seem able to gain actual sustenance from the act - the daemon seeming to be permanently weakened by the attack.
4: Ytdrt: Strange humanoid figures composed entirely of crystals, each one is the size of a Space Marine Dreadnought and roughly as strong. They are smart enough to follow the Crystal Blade's orders, and do so in both spirit and letter, though the exact motivation for this is unknown to all except the Ytdrt and Crystal Blades themselves.
Chaos Marines
1: Sharded Mutilators: The Mutilators among the the Crystal Blades have weapons composed of the same crystals that grow on most of the surface and much of the wildlife of the planet of Tibuna. Due to this, Sharded Mutilators seem to have gained the odd ability to leave behind crystal shards in any foes they strike, shards that they can detonate at will should they feel the need.
2: Shard Guard: Crystal Blade Marines encased in specialized power armor that has been enhanced with modified versions of the crystals of Tibuna's home world. This armor's enhancements and unique nature causes it to reflect energy weapons and psychic powers back at their users. Due to this, the Shard Guard are often deployed against foes that the Crystal Blades will expect to use either energy weapons or psychic powers themselves.
Chaos Sorcerers
Dreadnaught/Helbrute
1: Hellgaols: The Crystal Blade would not dream of imprisoning any of their brothers within the horrific confines of a Hellbrute. Instead, they imprison enemy Marines in them and control them with a set of crystalized 'receiver' bolted into the hellbrute itself. These rods will kill the unfortunate soul if disabled in any way. Naturally, this is fine enough in the eyes of the Crystal Blades as imprisonment in a Hellgoal was something they only ever did to their most hated enemies anyway.
Vehicles
Daemons
1: Palanquins of Tzeentch: Large floating platforms made up of multiple Disks of Tzeentch bound together, a Crystal Blade Sorcerer on a Palanquin of Tzeentch make usage of their warbands empathetic abilities to coordinate with each other beyond what most other warbands can attain, letting them achieve massive ritualistic effects on the battlefield even without an exceptionally powerful
individual sorcerer being present.
Daemon Engines
Chaos Lord
Chaos Sorcerer Lord
Xenos
1: Crystal Avengers: Dire Avengers wielding wraithbone armor that has been mixed in with a refined variant of the crystals native to Tibuna. Because of this, the Crystal Avengers are far more durable than the Dire Avengers of the Craftworld Eldar, and in large enough numbers can even aid the dedicated psykers they fight alongside in psychic combat… so long as they are not already preoccupied in a fight of course.
2: Far Schemer: A nickname given to the Crystal Eldar Farseers, who ironically enough do not have the same problem of eventually transmuting into psychically sensitive crystal that their counterparts do. Still, the life of a Far Scheme is a peril filled one, for while the Changer of Ways protects them from the depravities of the Dark Prince He is a fickle and flighty master. Thankfully, the Eldar's innate mutation resistance does offer some protection, but a Far Schemer must always be prepared for when their distant master decides He wants to have fun at their expense.
3: Chaos Warlocks: The 'basic' Craftworld Eldar warlocks but sworn to Tzeentch with all of the benefits and problems that implies.
@undead frog I made another list of unique forces, this time for Tzeentch. Can you make it an informational threadmark?