Before Post-Processing

After Post-Processing

First, duplicate the layer with the character

Copy the character to a new layer ↓ Apply Gaussian blur to taste (I usually apply a 40-50px blur if my image is 2000-3000px)

Set the layer mode to "pin light"available on CSP, SAI, Krita, & Photoshop

Adjust the levels for the character to taste

Duplicate the "pin light" layer and change the duplicated layer mode to "screen"

Adjust the levels until satisfied

Experiment with various levels of transparency or changing the "Screen" to "Overlay" mode to create different atmospheres