The toon shader in blender is a lot like their GLSL toon shader (except for the auto-smoothing) which runs quite fast. I'm hoping to take some hints from that to create a GLSL toon shader in-game. Then we just need the edge shader. SubSurf mesh (Subsurf level 3) Actual mesh (SubSurf off)
right now there's no real toon shader, however you can achieve some toon like effects with the skin diffusion shader. if you set the shadow smoothing to zero, you get a super hard edge which can look pretty cool.
This is a timelapse tutorial to show how to make Blender Toon Shader with Eevee for 3D character model, which the steps is absolutely for Beginners. https://www.cgian.com/2021/11/blender-toon-shader-tutorial-3d.html