Haunted by teleporting bruiser.

3 times now it has happened. First time I were chasing some rouges, and just when I had one aimed down with a sniper on his head "whack" I was insta killed from a blunt force blow to the bck of my head. Second time, I was in a building. I just scanned it, there was only one enemy left and we were having a faceoff. He were down to one armour bar and his HP "whack" I died. I was annoyed now, and decided as any would, to go back and pick up my shit. I ran out of the saferoom and across the street, "whack", and now I'm writing this. I'm scared, please send help. Bring Pizza.