I first added ClearView to intensify and darken the lower RH corner. This made the rest of the image too clear, so I lowered microcontrast. I also changed the WB setting to make the corner cooler - all of these in a single local adjustment.
Lowering microcontrast counteracts ClearView, so I had to see how far I could go.
If you click on the image or download it, you’ll also see the frame(s) I added: a thin black line surrounded by a white frame. The white line inside of the black line came from the conversion caused by the forum software, when it reduced the image’s size.