The most important asset is the 3D model (fbx) of the rexouium with the custom blendshapes I made, which includes:
I also share an avatar project, that I also call Ultirex, with everything already setup, such as:
-> Textures are compatible but may look slightly distorted due to the difference in shape with the ultirex
-> For clothes and accessories, you might need to adapt them if it clips with the muscles (playing with bones scales in unity or even sculpting in blender)
go to my discord : https://discord.gg/bC6U4GwbAt
make sure you own the base rexouium and that you have the role "Owns: rexouium" in the Rexouria discord (https://discord.gg/rexouria)
send me a DM to ask access to the ultirex rooms in my server
Enjoy !