What buff do cyclops and minotaurs use that makes them so difficult to finish off?

[Masheenz]

I ran into this earlier with a mission team but in that instance we had to debuff 1000% regen glitch to take down the arch v. Envenomed dagger temp power was used to finally defeat it. So what is the buff that these guys always put up right before they are defeated? I made a video in case someone wanted to see how cyclops react for educational purpose. 

 

[Psyonico]

I believe it is Unstoppable, which grants very high resistance to all but psi.

[Lost Cosmonaut]

I think that is Unstoppable: https://homecoming.wiki/wiki/Cimeroran_Traitors#Cyclops

[Triumphant]

When you're just fighting one by itself, when that buff kicks in, just save your energy and evade the big lug until it runs out.  Once the timer runs out, you can burn it down really quick.