Two of my favorite cards have always been Hypnotic Specter and Nightmare. Shades fit in to the swamps matter theme, so this deck has a shade sub-theme. This deck isn't overly competitive, but it is a lot of fun if you can get the game to go long and you don't have to deal with any enchantments. I avoid most tutors because I think it takes away from the randomness that EDH promotes. I've kept one as I think Beseech the Queen is pretty fair and I think one is fair.
The deck really plays lots of removal and hopes to stick a shade or swamp monster to make big swings as you start to accumulate swamps. A Nightmare Lash or a Lashwraithe on a swamp monster or a shade is normally game over if its not dealt with. Drains can finish off low life opponents or keep your health up early game. I waffle a lot of keeping Exsanguinate in because its borderline un-fun, but right now its in. Like all mono-black, it get ravaged by enchantments and artifacts.