The easiest approach would simply be to utilize the Abnormal addon, where you can find here for more: https://github.com/bnpr/Abnormal/tree/v1.2 Tutorials: https://youtu.be/cCEDmxFjQ3k
After downloading it as instructed, you could: Select the vertex normals you want to edit in edit mode, and average them. This will give the Guilty Gear Look you want for the face. This is how Arc System works snap the face shadows. However, the addon is very flexible, and many of us in the BNPR use it in various ways.
This tool reflects upon the same type of tool Arc System works utilized in SoftImage. There's no better tool than this for what you're looking for.
Guilty Gear's preset before making the game can also help give you a perspective when editing normals: https://www.youtube.com/watch?v=iH3p8N7qbv8