This deck is made around the idea of retaining board control with a couple powerful or mid-range buffed minions while holding on to board control spells and replacement minions.
All cards that you can see only one of are there to counter specific plays but mostly a warrior rush-down with the exception of mind control witch once you get to where you want to be in a late game is wonderful.
How i play it: Some damage is always expected as long as it doesn't bring you below 16 health. Starting off by countering small drops with the least amount of value spend. Thoughtsteal can provide you with additional options if there is nothing significant to eliminate. All enemy decks have a limited amount of small drops and once you counter about 6 of those you can expect the opponent to start bringing the big guns. and by that point you can tell just by looking at your hand you have already won.
This deck beautifully counters most tactics such as rash-down, mid-ranged board control, and late game big drops. Eventually wherein your opponent down forcing him to give up and quite... or at least that's what happens most of the games i used this deck.
You can always replace the loothoarders with nat or bloodmage ofc if you got em.
Edit: i have replaced the Harvest Golem for Mad Bomber because some of the time the opponent has problematic minions at start and the deck could use the extra damage. Also swamped Acidic Swamp Ooze and the Temple Enforcers for a Mountain Giant, a Molten Giant and a Sunfury Protector. To improve defense and offense. you don't want too many of either of the giants. Chances are, the way this decks plays out, your going to be able to use them effectively but you don't want to depend on them.
EDIT 2: after a long time this is the 3rd and final major change on this deck. Going back to the initial ideology of controlling the field and trying to maintain bout 2 huge creatures at the same time to burn your opponents field control cards leaving him/her with nothing much to play with. The addition of a few cards makes for some useful synergies as well as taking advantage of some of your opponents combination while at the same time exploring his/her strategy.
Thoughts: with Shadow Madness there was no longer a use for the Shadow Word: Pain as they have similar affects but Madness can deal more damage with less sins small pigs to your health aren't threatening with your hero power. Sylvanas left room to be countered too often while Gelbin can soak up more plays more efficiently. Ysera is really there just for giggles or for the occasion you end up in a vary late game and you just don't want to risk it.