I have tried to do bishop so much I have look up so many stratiegies and none of them have worked is he impossible I have used billy the kid's musketeers mastery and that didn't work and none of my other companions are doing any good so I think this is impossible.
Just bring a friend. I know I wouldn't have survived half of the fights in The Spiral without my friends helping me, and it's to them that I owe a big fat THANK YOU. Just yesterday my friend and I completed this dungeon, and although it was very difficult for me, we managed to survive both fights with Bishop with half our health left. It was overall a very enjoyable dungeon and I took like a million pictures, but, my point is, if you bring a friend, anywhere in The Spiral will be loads better.