Hearthpwn

The basis around the deck, isn't necessarily OTK, but you can OTK. Most deaths occur around turn 5 or 6. You play around the Naval Mine in the deck. There are many ways to proc the Naval Mine, but also many ways to make sure you draw the cards you need so that most games you aren't just hoping you get the magical exodia combo off. There is only one really big weakness that I've come across, and thats armor stacking warriors. I haven't had too long to test the deck into lots of other decks, just a couple days of testing so far, but so far so good. 

Mulligan: The perfect mulligan is to get Necrium Blade, Snowfall Graveyard, and Naval Mine (add a backstab to that if you are 2nd to go with coin). 

Necrium Blade + Snowfall Graveyard lets your Naval Mine fire off 4 times for 16 dmg. If you hit them with your weapon, thats and extra 6 dmg to make 24. Then finally, if you can kill your Naval Mine, thats 32 dmg. Because Snowfall Graveyard lasts for 3 turns, it lets you setup the combo at most, 2 turns in advance and is super useful for the fastest kill. In the most perfect setup, you can get a turn 3 kill. If you have Nec. Blade, Snowfall, Naval Mine, and Preparation in your hand on turn 1 (you have to go 2nd for this), then you can preparation turn 1 and play Snowfall. Turn 2 you play coin and Nec blade and hit face for 3. If you draw backstab on either turn 2 or turn 3, its an autowin. On turn 3 you can play Naval Mine and then hit face to destroy your weapon to deal 19 dmg and then you can play back stab for another 8 dmg by killing the naval mine and GG. Perfect turn 3 kill on Rogue. Never seen that before lol. 

Necrium Apothecary allows you to basically draw your Naval Mine if you cant find it. So it doubles your chances of getting the card you need. It also can act AS a Naval Mine since it copies the deathrattle and lets you draw the Naval Mine. I mainly use it to just draw Naval Mine. Potion of illusion just lets you copy any minions, you can probably even swap it out for something else beneficial. Vanish really helps with clearing the board and just an overall stall. I tried Doomsayer, but it didnt really do as well because of them being able to easily clear it. Also, it counteracts Shroud of Concealment because it adds an extra minion you have to draw and lessens the profitability of Shroud since you're using it to draw Naval Mines. 

Cavern Shinyfinger guarantees you to draw Necrium Blade. So even if in the mulligan, you get Shinyfinger, keep it because then it at least guarantees you to get your weapon instead of trying to swap him out and get lucky. 

Reflecto Engineer is useful in some cases because if you just are super unlucky and not drawing any weapons, but you have snowfall graveyard, you can swap the health of all of your mines and when you play them, they instantly die and activate their deathrattle. Think of them then as 2 cost 4dmg to hero cards instead of minions. 

Sketchy information guarantees you either Nec Blade or Naval Mine. If you have Naval Mine on the field, but no Nec Blade, you can draw it and still activate Naval Mine's deathrattle for free and then guarantee you getting blade for a 2nd activation. It's also vice versa because if you draw Naval Mine with it, then you still get the free 2nd activation of it's deathrattle. 

Togwaggle and Smokescreen are some fun additions to the deck. You can add 10 mines to your deck and then smokescreen and deal some fun damage that way. Obviously you can disregard those and do something else in the deck, but I'd stay away from minions for the absolute max chances of getting all the cards you need for a turn 4, 5, or 6 win.