Dark/shadow skins

Hi. At first I would like to introduce myself. I'm playing lol since it was released (but i forgot password for my 1st account then i created this one in seson 2 :P). I'm playing only ,,evil" chracters (main , ) and i love that climate of spooky/scary/evil/dark/shadow characters (i love shadow isle and void ) and i have request... A lot of champions have bright skins ( , , , justicar , [...]) and this can be climate when you can play good vs. evil (like noxus vs demacia he he :P). Is there any chance to add shadow skins in game? (Personally i wish Riot could add shadow , like Hermaeus Mora from skyrim)