The Sick Bet

Pretty much the fished sketch.

I put gradient layer over the whole picture and put on "color" in the rendering styles.

I merged the picture into 3 parts (the monster, the person, and the environment). I put a clipping mask on the monster and person layers along with the base colors.

I erased the sides to have it merge into the background for a consistent feel.

I made a new layer with the whole image and put a gradient map on it, I set the layer to soft light with 25% opacity.

Brushes I used. 1 default and 4 that I made myself.