Darth Smith, commonly known as Darth Who?, was just like any other like any other Sith Mega-Super-Overlord, except for the fact that he didn't do anything slightly unique in his lifetime. I mean, all Siths are basically the same, except each one usually does something special, like cook some food or something. But Darth Smith didn't. He was sorta just there. Sure, he destroyed some planets and killed some Jedi, but what Sith Lord hasn't? Please. This guy was probably the most insignificant Sith Lord in the entire Universe ever, even more insignificant than that guy.
Regardless, Darth Smith was still pretty cool, probably because of his sweet shades.