I am trying to make a pillar cloud using an image transparency. I have a basic node set up for making the image show with transparent background. But I would like to make the cloud pillar glow. I am not sure how to set up the nodes to make this happen. I am using Blender 2.79
Given that you are using an image to determine transparency, you can change the brightness by using any of the following nodes: gamma, color ramp, Bright Cont or even a Converter>Math node to affect the values.
To make things glow there are already endless posts on the subject in this site.
Start with this one: