First a word of warning.  As the name suggests, this deck does not play consistently.  I like it best in a three-or-more player free-for-all, as you will not appear to be a threat until your opponents have all softened each other up for a bomb.

This deck's mana curve is whacked, intentionally.  There are a total of 7 cards that cost less than four mana, and only 1 that costs only four mana.  The other 28 non-lands cost 5 or more, and fourteen of them cost 7 or more.  This is intentional.  The deck is mind-numbingly slow, but when it does damage, it does not screw around.  Erratic Explosion paired with this deck setup means that only 1/5 of the time will you do <5 damage.  And 2/5 of the time you will deal 7 or more.  Additionally, many of the cheaper cards, like Darksteel Pendant and Goblin Spy, allow you to see your cards coming, removing the element of uncertainty entirely, and giving you some control over what Erratic Explosion will do.  Volrath's Dungeon gives you even more power.  Put the Polar Kraken from your hand onto your deck and you'll explosion for a guaranteed 11 damage (for a mere 3 mana), killing your worst creature or knocking your opponent down to your level.

Psychic Battle is also useful, if used judiciously.  Keep in mind that it does NOT change the card at the top of your library.  If you use the Dungeon to drop the Kraken or Stratadon there, it will stay put until you next draw, allowing you to effectively choose your opponent's targets throughout their turn.  However, it can just as easily mess up your Explosions if you aren't prepared - an early land draw won't usually bother a blind explosion, but if you're suddenly targeting yourself, it could ruin your whole day.  Anarchist and Eye of the Storm give your Erratic Explosions more oomph - the one lets you play them twice, the other (if you can get it out) stacks them one on top of the other to multiply your damage potential.

Affinity and morph are also employed to offset the serious speed disadvantage here.  Scornful Egotist is great explosion fodder, and for three mana you can turn it into a 2/2 (for another one mana you can turn it face up and blast for eight damage with Torrent of Fire).  The Hoverguards and Enforcers are classic affinity cards, which, paired with the artifact lands, tend only to cost four or five mana at most.  Broodstar is nice if you can pay for it, but it's better as a discard to the creature-hungry Dralnu's Pet, who will turn it into a flying 12/12 for six mana.  Clone Shell is another way to get a card into play that you have no business playing.  Play it with Jin-Gitaxis on the way for an especially horrible surprise.

Parallel Thoughts is one of the most powerful cards in this deck if you can get it out.  If you do, remove all the cheapest cards left in your library.  (All Erratic Explosions included, and Torrent of Fire, too, if you like).  This will raise your Erratic Explosion damage potential significantly, as well as allow you to dramatically increase the likelihood of drawing them, and Dralnu's Pet.

Your major concerns will be in the early game.  Blocking with morphed Scornful Egotists is a necessary evil.  Try and get the Myr out as quickly as you can to remedy this.  Venser's Journal can keep you alive for a while, especially if paired with Rush of Knowledge, Thoughtcast, or, if you can afford it, Jin-Gitaxis.  Using Erratic Explosion to burn creatures is disheartening, but often the only way to stay alive.  I recommend going for your opponent's throat whenever you can.  If you can survive another two or three turns of creatures and your opponent is at <15, go for the kill.  One good draw is all you need in this deck to win the game.

Also, feel free to swap out the clunkier high-cost cards for even higher-cost cards.  Polar Kraken is an easy swap for something scarier - Draco, or Autochthon Wurm or Emrakul.  Mycosynth Golem is another sweet addition to the deck, especially if you choose to go heavier on artifacts (Blightsteel w/ affinity, anyone?).  For the less scrupulous player (and one not playing tournaments) sneak a Gleemax into the deck to end your friendship with your opponent.