This civilization of people came from an alternate dimension where time flows differently; somehow they were simultaneously in the far future and still in BR 1,989. Of course, this means advanced technology with 80's retro flair.
A small portion of their sprawling empire was ripped through the dimensional rift and spit out into this new universe; lacking a homeworld and military infrastructure, they look to capture a new world for themselves and rebuild the empire.
Infantry

The Collective's fighting forces are mostly women. Men who join their military are often trained as pilots or for supporting roles.
Standard issue weaponry is a laser rifle.
Shock Troops

While most of their weaponry is laser-based, traditional firearms and hand-to-hand weapons are occasionally seen in the hands of elite squads.
The Plastic Lover

The dimensional rift had some strange side effects. One of the officers caught in the rift had a prized vinyl album with him at the time, and the rift transformed the album cover into a sentient being. Her voice has the power to manipulate time and space.
BWC Light Fighter "Tsukiakari"

Swift and nimble, and armed with four laser cannons. The shape is inspired by a crescent moon, but the rear wings are also anti-grav stabilizers.
BWC Light Gun Platform "AD86"

This particular vehicle was adapted from a civilian sports car; this model had the necessary speed and power even when fitted with a very imposing laser autocannon.