These are Proto-synthetes, there are many versions of these, this is the ranged version.
They have a mortar skill similar to Forged Frostbearers but about 1/4th of the damage and the element they use is fire.
Their overlap is more reliable however as they have no Innate projectile spread.
As you can see in the video, the returning projectiles are not something that fits them.
These can be found in Distant memories and cortex maps.
This video was recorded in patch 3.21.
