ohh yes it can be used as skin, thats what it is for ... all you have to do is backup original player.dff and player.txd in gta.img and add then delete them from gta.img...
Then add my files in it, if it is not named properly then name them. then just rebuild achieve. (if you are using img tool)
Then just rename picture (player)in gta vice city folder/models/generic to any other name. you are done when you load the game Metal Gear Rising Raiden Render is ready!