"I am the Hammer. I am the Sword. I am the Gauntlet. I am the Bane of foes and the woe of the treacherous. I am the End."
- — Grey Knight Prayer
A Nemesis Force Weapon is amongst the most potent personal melee weapons that can be employed on the battlefields of the 41st Millennium by any faction. Each individually-crafted Nemesis Force Weapon is a potent combination of advanced power projection circuitry and arcane psychic arts.
Nemesis Force Weapons are extremely difficult to manufacture, which, along with their high quality, makes them rare in the Imperium of Man. The ability of the weapon to channel the psychic power unleashed by a psyker into a lethal strike makes them devastatingly powerful weapons in close combat against psychic or Warp-tainted foes.
The power unleashed by the Nemesis Force Weapon directly corresponds to the ability of the individual psyker. A Nemesis Force Weapon is especially effective against the foul forces of Chaos.
The main users of Nemesis Force Weapons are the Astartes of the Grey Knights, every one of whom is a powerful psyker. The older variants of the Nemesis Force Halberds traditionally used by the Grey Knights incorporated a bolter mounted on the forward end of the staff above the blade. The newer versions of these Nemesis Force Weapons no longer incorporate a bolter, as the Grey Knights now make use of a Storm Bolter mounted on the wrists of one of their armoured gauntlets.
The Grey Knights possess some of the finest weapons and armour known to the Imperium and are well-equipped to maintain and use them as part of their sacred duty to the Emperor. Since they are supplied directly by the forges of Mars, few other military forces, including other Chapters of the Adeptus Astartes, can boast an arsenal that even approaches that of the Grey Knights.
On top of the fine craftsmanship of the Tech-priests and magi, the Grey Knights also incorporate many psychic wards and potent blessings into their weapons and armour to adapt them to face the threat of the Daemon and the Warp. A Grey Knight's weapon and armour are sacred to him, cherished possessions which he cares for and maintains so that they might never fail him in battle.
The weapons of the Grey Knights are fabulous artefacts far removed from the common Stub Guns and Combat Shotguns that line the racks of weapons dealers everywhere in the Imperium. These are weapons crafted by the best magi of Mars, or the Grey Knights' own Forge Masters and Techmarines, specifically for the warriors of Titan. For this reason, they are never for sale, and they are so insanely rare that they are practically never found outside the hands of a Grey Knight.
Of course, Grey Knights and other Adeptus Astartes wargear and equipment does occasionally find its way into the hands of nefarious individuals and black-marketeers, though this is extremely rare.
The most distinctive weapon of the Grey Knights is probably the Nemesis Force Sword and its other melee variants. Finely tuned to the psychic wielder's mind, it is a perfect weapon to use against Daemons and other denizens of the Warp.
Nemesis Force Weapon Variants
This weapon was developed by the Ordo Malleus as the ultimate weapon in daemonic destruction.
Nemesis Doomfists are only found as part of the Dreadknight battle suit. Those struck by a Nemesis Doomfist swiftly discover that though the occupant of a Dreadnought may be crippled in body, his psychic might is as formidable as ever.
Wielded as a pair, Nemesis Falchions resemble shorter versions of a Nemesis Force Sword, with a much smaller hook-ended blade. Nemesis Falchions can be carried by a Grey Knight with a Storm Bolter thanks to the Storm Bolter's wrist mounting.
When the weapon's monofilament Nemesis circuitry is triggered, a Grey Knight can wield these blades with incredible speed, striking multiple blows in the time it would normally take for only one to fall.
Nemesis Force Halberd
As ancient in design and purpose as the Grey Knights themselves, Nemesis Force Halberds are finely crafted polearms with long, curved blades and sturdy hafts. A Nemesis Force Halberd comprises an iron and silver blade set atop a long adamantium haft.
This extra reach is invaluable to a Grey Knight, often allowing him to land a telling blow before he is within reach of the enemy's own melee weapons. A Grey Knight can easily use such a weapon one-handed in short deadly chops. However the weapon becomes even more dangerous should he wield it two-handed.
Nemesis Force Sword
The most common type of Nemesis weapon, the Nemesis Force Sword exemplifies an amalgamation of sorcery and science. A lighter version, of the force halberd, a force sword can take many forms. Force swords are crafted using arcane magicks and complex scientific formulae and incorporates a power field like all Nemesis Force Weapons.
The blade is tempered iron, flecked with shards of silver and inset with ancient runes of Daemon-slaying.
In contrast to these primitive materials, the haft and hilt of the sword contain advanced Nemesis power field generators. The balanced grips and nearly indestructible construction of these weapons makes them perfect for parrying the attacks of even the most powerful daemonic foe.
Wielded only by the formidable Nemesis Dreadknights, these colossal greatswords consist of a massive blade of silver and iron so large that not even an Adeptus Astartes in power armour can lift it. Despite its immense size, it is perfectly balanced in the hands of a Dreadknight, and is a powerful tool against even a Greater Daemon.
Nemesis Warding Stave
A Nemesis Warding Stave's abilities are defensive, rather than aggressive. Designed as a defensive tool, the Nemesis Warding Stave can be used in melee combat to protect a bearer from attacks that would breach even the armour of a Terminator.
The hollowed-out haft of the stave contains several Refractor Field generators, which the wielder can prime with a charge of psychic energy. Thus activated, the stave projects a zone of protective force similar to a Conversion Field around its wielder, granting him enhanced resilience against his enemies' attacks.
- Codex: Grey Knights (5th Edition), pg. 54
- Dark Heresy: Daemon Hunter (RPG), pg. 131
- Gathering Storm - Part Three - Rise of the Primarch (7th Edition), pg. 124