The least you could do would be to try and make a new texture for one of the existing hoodies (in case you wanted to make a simple hoodie). If you wanted to make a whole assassin outfit, you would need to have good 3D modeling skills, texturing skills, and also tools that we yet need to make, and I don't believe that's going to happen anytime soon. Either way, it's up to you. You can try to retexture any existing hoodie, and if you succeed, share it with us! Good luck!