Darn it, would you answer the question? It might be the difference between being able to achieve this hare-brained scheme, or not.
The little "bite" out of the mask in the top right corner - is it important?
Ok, now we're getting somewhere. I still don't understand why you wasted so much of our time with that Gradient Map nonsense.
Now, please address this question:
It makes absolutely no sense; and I think if you stopped to think about it you would see that.
To what kind of layer will this C-shaped mask be applied?
You keep saying "gradient" but your screenshots are of Gradient Map layers, which are a very different thing.
So I need you to explain the situation further. Why are you using Gradient Map layers?