"Fixy" is an original character created to illustrate the techniques that GuiltyGear and GBFVS GranBlue Fantasy Versus use to stylize their shaders.
Fixy comes with Part 4 of 4 as part of the files and assets. You can apply these techniques to any of your characters in Blender's EEVEE real-time viewport. You can check Part 1,2,3 and 4 for details about their content in the links above.