Hearthpwn

This deck is my own tweak on the standard mill rogue seen when you look up mill rogue. The main difference in my deck is the removal of beneath the grounds and SI:7 agent in favour of a few anti-aggro draw cards (shiv and fan of knives), and dropping 1 preparation in favour of Reno Jackson. 
With this set up, you have 4 draws in the deck to help you find coldlights that simultaneously can be used for creature removal, the first of which aids against any deck ,and the last of which specifically helps vs aggro.
Drawing up to 4 cards with these cards is totally fine: you're going to put 6 cards into your deck with 2 Gang Ups, and in case you would still die to fatigue damage first because 2 cards isn't enough of a buffer, you have Reno Jackson to put you back up to 30 health when your deck is almost/entirely gone. Lastly, it's not like you have to use them to draw if they are among your final cards. While this deck still isn't very consistent outside of a control meta, it does give you a slightly higher win rate vs the deck's nemesis, Aggro, while actually improving vs what it is favoured against, control, with the card draws.

Instructions:

Mulligan:

Hard Mulligan for Coldlight, always. That's really about it. If you are facing what you are sure is aggro, you could risk keeping a deathlord, but coldlight is so central to the deck that I still wouldn't recommend it.

Replacements:

Reno Jackson can be replaced with Antique Healbot, which can even be ganged up.

Emperor: He isn't actually completely necessary, though certainly nice. His effect often translates into a 1 turn taunt if you're not already facing lethal, which can be very useful for this deck (on top of the obvious mana cost reduction). He could be a second preparation though, or just something else entirely like SI:7. Other descriptions for this deck include Loatheb as a potential card, but I don't think he would offer much value personally, and certainly not as much as Emperor.

Blade Fury: With Poison, this is a strong removal card, so dropping it is difficult. The only thing that does nearly as well (and not as well, frankly) is betrayal. If you really don't have blade fury, use that.

Preparation: nothing replaces the preparation. You need 1.

Brann: Irreplaceable. This is more important than the 1 preparation.

Coldlight: Get out of here.

Modifications:

If there are a lot of Aggro's at whatever rank you're at, you could try to swap out the 2 shivs for 2 Antique Healbots, but it's not likely to make that much difference. But maybe.