Deepen is analogous to Highlights.
Lighten is similar to shadows.
Highlights and Shadows can affect contrast (especially shadows). On the other hand, Deepen and Lighten maintain overall image contrast.
I would not say that Deepen negates Shadows, because Shadows works on the left (dark) part of the histogram and Deepen works on the right (light) part of the histogram.
Black Point is not related to either. Black Point is the definition of black (zero). If you raise or lower the black point, it will affect any adjustment that works on the shadows or darker parts of the image.