Untouchable Gunner Corrupt Rescuer
I just had a fight against a team in the arena. The battle started normal and he killed some of my toons and I killed some of his. Then he only had his GCR left with half health and a full Titan shield. It was my turn and I was going for the final kill. Then to my surprise his GCR did not take any damage! Neither his shield or healt went down no matter how hard or often I hit him. He was just untouhcable! I tried for many rounds, but nothing affected him. He just went on as normal and reveived his teammates. I killed the reveived toons, but not GCR. Unfortulately I did not have any toons who could try to remove or steal beneficial effects alive at that point so I can't tell if that could have rescued me. Eventually I had to take a draw to end the fight...
I read from the ingame update notice under known bugs that GCR's passive either never works or always works. But that is noted under the Prisoner which I don't have.
EDIT: In the end I only had the Nomad left, and since I only had one toon left it could be that GCR's shield was reset immediately after my hit which would explain why I could not see that the shield was taking any damage. If this is the case then you are pretty much fu**ed if you have only one toon left against GCR even if that toon is a hard hitter like the Nomad...