Hard light stave
From Halopedia, the Halo wiki
|This article is based on canon information, but the article's name is conjectural, and/or uses descriptions as the title, as there is currently no official name for the subject.|
Hard light staves are a kind of melee weapon produced and employed by the Forerunners, notably their armiger constructs. They are sometimes colloquially referred to as energy staves, though are distinctly different weapons to the energy staves operated by the Covenant Honor Guard. Instead, they operate on a principle more similar to the Covenant's own hard light glaives, employing hard light as their primary mechanism.
Hard light staves, as used by armigers, consist of a metal frame with a geometric blade of hard light at the end. While a distinct weapon in their own right, they can be formed in the heat of battle by an armiger should they be disarmed of their conventional weaponry, with the stave's staff forming from parts of the armiger's robotic arm. They can be used by their operators to spin at lightning speed and block incoming weapons fire. 
Energy staves, as described in Halo: Hunters in the Dark, seem to be based on a weapon concepted for a potential inclusion in Halo 5: Guardians, which was in mid-development around the time of the novel's writing. In the concepts produced, the stave would have been a weapon wielded by the similarly-cut enemy, the Forerunner Cavalier. The staves' use in the novel may have been inspired by these concepts (shown below). The Cavalier concept would ultimately finalise in the game as the Warden Eternal, who also wields a distinct lightblade.
One of the many concept pieces produced showcasing Halo 5's cut Cavalier enemy type, complete with a polearm. See here for more concept art.
List of appearances
- Halo: Hunters in the Dark (First appearance)