Full Shader:
https://godotshaders.com/shader/updat...

Fresnel Effect from Godot Shaders:
https://godotshaders.com/snippet/fres...
I used the "Basic Fresnel" from there

Hopefully you understand some of the concepts I used while making this shader. It always helps to have reference images and to study them. Look up online stuff you are confused about or ask someone experienced how to do it.

I should also point out that I'm not particularly an expert on shaders and I'm sure that there's better ways of doing certain things. If you do know of a better way to do something I'm eager to hear how to do so. The code is also on GitHub if you want to fork from it and improve on it:
https://github.com/nekotogd/Godot_BoT...

Unity References:
   • Video  
   • Zelda Breath of The Wild Toon Shader ...