Just to be clear from the get-go, this is a Dimir Tempo Flash deck (you won't be winning games by milling out your opponents).  There have been a few decks spinning around trying to take advantage of the new Thieves' Guild Enforcer.  The card is a super versatile one-drop for black.  It is both a mill engine, and has upside based on your opponent's graveyard size.  I saw that TheAsianAvenger at MTGoldfish played a 5-0 pioneer deck by AlexFiero that was based around the rogue concept and contained quite a few cards that are currently legal in standard.  That list was the inspiration for this one.  I took a look and realized that we have Faerie Vandal at the 2-drop slot to replace Glint-Sleeve Siphoner], and we can slot in some Slitherwisp to fill in card-draw, and pump up our Vandal.  We are also playing some Thought Erasure main deck as proactive control that starts getting cards in the yard.  We really want our opponents to keep cards in the graveyard as Drown in the Loch needs fuel.  Drown in the Loch is great, and I think is the best payoff from getting Thieves' Guild Enforcer into the format.  Now we have a better option than Merfolk Secretkeeper to enable us to play this on Turn 2.  The deck is coming from quite a different format, but the prevelance of low-cost spot removal feels good against Mono-green seems to be servicable against monored.

Thus far I've only played 3 matches in B03.  This deck dunked on a Sultai and Winota deck in Diamond Ladder B03.  I got stomped by an Orzhov Knights deck, but I did get flooded game 1, and disconnected from the server on game 2 (missing a land-drop, a turn, and discarding a Brazing Borrower to hand size), so I'm taking it with a grain of salt.  That said, we might need some Cry the Carnarium into the sideboard here to deal with wide boards and decks that get under our spot removal.  I brought in the Vantress Gargoyle's from the sideboard for this match; they're good blockers and can progress our mill plan, but don't deal with wide boards.

I should probably be playing some amount of Fabled Passage here, but I really want to keep 3 Castle Lochthwain in the deck to help us pump the Vandal later in the game.  Being able use our manabase to pump our gameplan is super helpful.  We realistically want to be closing out the game on turn 6 or 7, so using life as a resource is generally pretty beneficial to our gameplan.