Modding, copyright, and related issues.

Found a game that blatantly uses assets from Heroes 5 and 6. https://m.youtube.com/watch?v=xN6hbrTjkJ0 The other assets are probably also taken from somewhere. By the way, remembering the previous idea. How realistic is it, and what needs to be done to write a letter to Ubisoft asking for permission to use assets from Heroes 6, 7, and Dark Messiah for non-commercial mods for Heroes 5? Does anyone have any ideas, and is anyone interested in this?