What a shame if it is another skull of dire Ahamkara ornament. It's not like there is any reason to use that exotic now anyway.
For pure aesthetic it is amazing, come on, it's Riven's skull, who wouldn't want to don that!
Are you meaning one different to the existing ornament with the sharp spikes and pointed jaw bones? I love that ornament but unless the exotic is made to be worth using it'll never see any play. Just like some of the most amazing looking Warlock exotics. The stag. (Nothing looks more menacing than this one with the ornament) Wings of sacred Dawn.