Since there isn't a thread yet for the various Twili factions, I figured I might as well post here as this is the closest there is. As Eldren previously mentioned, the "twilight armos" could serve as a unit for. I, however, would like to add to that by suggesting another automaton join it - a larger, more brutish compatriot, perhaps better suited for combat and/or manual labor, known as the armos titan.
Given that the Twili are the descendants of Sheikah and Gerudo (amongst others), there may even be a way to fit them into the lore in a manner that combines the two cultures, as well as hinting at a darker nature for the construction of armos. In the original game, armos are stated to be "A soldier who has been turned into a stone statue." In later games, though, it becomes clear that armos are powered by glowing gems/crystals that must be destroyed in order to power down the automaton. Given that the Gerudo are capable of binding spirits to armor, such as the Iron Knuckle, which, somewhat coincidently, also appears to having a glowing gem/crystal on its body. The Sheikah have a similar method of containing, via Malmords, which could be viewed as being akin to the use of gems/crystals.
Combining these two aspects, perhaps the armos of the Twili could in fact be bound spirits/souls used as a power source, a means of giving their creations autonomous movement. Whether or not the spirits/souls are willing, or if the Twili that "donated" them has yet to have died, may be another question entirely.
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Another suggestion is to use the beta Shadow Beasts for one of the Twili factions. Their appearance is distinct enough from the Twili Messengers that I doubt they'd be confused for them, and lore wise they could represent some bestial native of the Twili Realm (planet) or, quite possible, Twili/Shadow Lizalfos that have been heavily transformed by exposure to the environment. The latter idea comes from the fact that they clearly have tails and somewhat reptilian-looking jaws and limbs.