Great stuff! This is very well made. Now not only do we have a “Diablo 3 Technique” for Unreal 4 but for Unity as well! That said, there is one slight thing I would like to point out that I feel would +1 this. It’s all about the “Noise” Textures. This is a very beginner friendly effect, and so I’m thinking in that “What-If” context. There is a lot of weight on the Texture for this effect as presented. A Keystone, if you will. Yet you made no mention on the creation of the texture which is so important to make this effect. Photoshop? Substance Designer? When you made these textures, did you know what they would be, or were you just playing around until you got what you were looking for?
Now, if I had to guess, you made these in Photoshop with Render > Clouds as a base, and then used some combination of Min/Max, Threshold, or even some “Art” Filter on top. Then you did the work with the shader nodes as shown and bing-bang-boom; Fire! 
That is my guess.
With that little quibble aside, this really is great. You did a fantastic job. Thanks. 