Okay this is my first serious attempt at a actual deck write-up, so please bear with me here. The idea of this deck is obviously to cycle through your deck as quickly as possible with Battle Rage , Acolyte of Pain, and spells that cycle themselves or assist the Battle Rage or Acolyte draw. When you gather the right cards play out a ridiculous amount of Arcane Giants using Dead Man's Hand and Blood Warriors.
Disclaimer: This deck very hard to play, I am not even sure if I have the right approach. Mistakes are very common with this deck and not every decision can be answered by a guide.
Fortunately the mulligan is one of the easier parts in this deck. Almost always keep Forge of Souls and Battle Rage in your opening hand but consider tossing the Forge if you are keeping War Axe and Battle Rage against aggro w/o a guaranteed activator.
Keep Fiery War Axe against Paladin (unless you know they are control), Mage, and Shaman. Keep Blood Razor and other whirlwind effects against Hunter, Paladin, and Shaman unless you already have Forge of Souls. Keep Execute against Warlock for Twilight Drakes/Mountain Giants, against Priest if you expect Silence Priest, and Druid. Other than that just keep any card that says "draw a card" and combos such as Blood To Ichor + Acolyte of Pain or Commanding Shout + Wild Pyromancer.
How to use Dead Man's Hand
The one of the first things to think about using Dead Man's Hand is deciding to go infinite or not since you cannot once you shuffle without the second Dead Man's Hand. As a general rule you go infinite against control decks and just spam the board against aggro and mid-range (except Paladin), but there are times when you will just lose if you don't go all in against control.
Pay very close attention to the content of your hand before you play Dead Man's Hand. Diluting your deck by even a little bit can mean drawing dead. The cards to avoid shuffling are weapons (one Blood Razor is usually okay, never multiple), Forge of Souls, single target removal, and Scourgelord Garrosh. What you do want to shuffle in your deck is Arcane Giant and draw, specifically Battle Rage/Blood Warriors + activators. Be wary that you only have one copy of Blood Warriors. The end goal is essentially going Dead Man's Hand -> Arcane Giants -> whirlwind -> Blood Warriors -> whirlwind -> Battle Rage infinitely.
I'll keep it short and dirty for now, but I'll probably add more detail if I have time tomorrow. The best match-ups are probably Rogue, Shaman, Druid, non-Quest Mage in no particular order. Worst is Paladin for sure.
Actually one of the easier match-ups. As long as you are able to Execute/Shield Slam an early threat you can usually cycle quickly enough to just spam the board with Arcane Giants, no need to go infinite. Consider only going 3-4 giants though if they haven't played Spreading Plague.
Remove their minions, gain armor. Double Savannah Highmane is a bitch to deal with though.
It is actually possible to out armor the Time Warp OTK but it's very difficult, you're probably more likely through the mage having a poor draw or running out of freezes for your Giants. Otherwise remove minions, gain armor, you know the deal.
If you are looking for a good Paladin match-up don't play this deck. They can deal with the Giants fairly easily and you have no effective way to deal with Spikeridged Steed or Tirion. Aggro Paladin is slightly better, but not by much.
Probably the second hardest class to face, Big Priest has too many high health minions, Control Priest is hard to get damaged for Battle Rage. They can deal with both a small or large board of Giants. N'zoth bringing back Obsidian Statues completely screws you.
Kill all of their minions, armor past their burn. Vanish + Doomsayer with Jades seems problematic, but I haven't played against it yet.
Evolve - Kill all of their minions. F
ree win LUL. But seriously, you really only have to worry about a good Doppelgangster + Evolve.
Control - Have not played yet but I imagine it would be difficult, especially with N'zoth.
Basically a race to who can get an unanswered board first. Alternative win condition is to punch them in the face with weapons.
Pirate warrior - Don't draw your dead cards.
Control warrior - If you both infinite, your draw engine is infinitely better. N'zoth is problematic. Possibly keep Execute for Rotface.
Mirror - Race for a Giant board.
Some cuts to the deck early on during the refining process were Forge of Souls × 1, Slam × 2, Whirlwind × 1, Fiery War Axe x 1. The second Forge of Souls usually draws nothing and since you cycle so quickly and will mulligan for it there is a high chance that it will draw 2 cards. One Fiery War Axe was cut because once again you will keep it in your mulligan in a decent amount of match-ups and having multiple War Axes in your deck or hand is just extremely clunky. Slam and Whirlwind didn't do enough in my experience since I almost always would have a better play, but you may include them if you feel the need too. If so cut Shield Slam × 2, and Shield Block x 1.
The main point of Scourgelord Garrosh is the Hero Power providing Whirlwind effects without actually needing the cards in your deck. Also helps get multiple triggers in a turn such as whirlwind -> Blood Warriors -> whirlwind -> Battle Rage and Armorsmiths. The weapon + Hero Power is pretty effective against Spreading Plague, which is nice. It's also 12 face damage if needed.
*to be added*