Need Help Creating 2D Flame/Aura Outline Shader

I want to add a particular type of outline to all of my 2D sprites in game. It'll form an important part of the game mechanics but it's the one thing I keep putting off because I just don't understand shaders.

The outline will need to look like a flame/aura that animates at a fairly low framerate and look good pixelated. Also I wouldn't want to mess about with anything that takes up insane resources (I saw one video where someone overlapped 100's of particle GameObjects to create a similar effect!)

Here is a really rough idea of what I'm going for (note that it looks bad because drawing flames by hand is surprisingly difficult for me):



I also found a YouTube video showing a fire outline shader that seems promising in producing a similar effect

I'd prefer an off-the-shelf solution (if it exists). A short script that forms a proof of concept. Failing all of that I suppose I would pull up my sleeves and learn how to do it myself or else pay someone else to do it. But even in those cases I wouldn't know where to start.

Any advice as to what direction I could/should take would help me out a lot as I'm very much lost at sea regarding shaders!