>What is Toon Shader?

Get it and read about it from here https://hanmen.gumroad.com/l/ilywp
Please consult Hanmen or Illusionsoft community for more info about the shader

>How do I use these files included in this package?

You don't need to use all of them, pick the method listed here according

The card:
1) Copy the card to card directory (as you would do with HS2 cards)
2) Load the card in chara maker/studio
3) That's it, no DHH or Graphics Mod necessary

Texture Files (For Advanced Users):

1) Load the original card of this character or your custom card that used this character's face in chara maker
2) Open Head Material Editor, change the shader to "Hanmen/Toon Head" OR "Hanmen/Toon Head Cartoon"
3) In "Outline_Sampler" slot, import included .png file that has "outline" on its name
4) Change the body, hair, and clothing's shader as well with Material Editor accordingly
5) Save the card

Notes & FAQs
1) Applying the shader to the hair will make said hair darker, so lighten the color again in color tab

2) I noticed that neck seam is minimal in chara maker but can be more visible in studio depending on preset used

3) Q: Why this roundabout way? Some other head mods I know don't need this and compatible with the shader right away
   A: Because of the UV in my custom head does not aligh perfectly with default UV. Other modders may made their 
      custom head align perfectly with default UV that is good for maintaining compatibilty with default assets
      (such as make-up). However, I have my personal reason to keep the custom head's UV unmodified as much as possible
      even at the cost of compatibility in make-up and this next-gen shader

4) Q: I found new error
   A: Report to me and I'll see what I can do. However, I'm still not very familiar with how the shader works or 
      using material editor in-depth so I might end up as confused as you are.

5) Q: I have general question about toon shader
   A: If it's not related to my mod, it's best to ask community like Illusion-soft discord or to Hanmen as the creator