On this page of the Steelrising guide you will learn how to defeat the mini-boss called Unstable Forger.
At close distance, this opponent attacks with a hot rod inflicting burn. However, the Forger is a very slow opponent. Admittedly, he can run up a bit and attack forward, but this move is still pretty sluggish.
His skills also include crouching down and creating a heat wave that can set you on fire. In addition, he quickly swings the rod, damaging a wide area.
Unstable Forger is very susceptible to frost. Try to attack the mini-boss with a grenade or a pistol capable of turning an enemy into a block of ice. Once you succeed, run up to the enemy and attack a few times until he frees himself - keep doing this until you win.