How to fix 3D toon shading shadow issues?

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:bust_in_silhouette: Asked By neverbegameover

Hi, I am having some issues with the lighting system in 3D.

After applying the default toon shading and setting the roughness to 0, the shadows on the character produce these weird smudges. I heard this was self-shadowing, but all of the fixes listed for it did not work for me that well.
I tried adjusting bias, but that made the shadows move away from the character since I had to set it to a high value to eliminate this completely. I attempted to use contact to offset this, but that brought the same issue back in a much worse fashion, even breaking the shadows of the surrounding walls.
I know there is a flag to remove shadows casting on the material, but that is not the effect I want. If the character moves under a shadow, I want it to gradually turn black as it normally would.
Is there any other way to mitigate this? Or am I stuck for good?

For reference, if necessary, the style I am trying to emulate is that of “killer7”.