Hearthpwn

I took chudbabies' advice and took out Hakkar, the Soulflayer. I think Hakkar can be useful in Warrior decks, but in this deck there isn't much synergy with the other cards. Also the number of combo decks on ladder decreased a lot with the recent nerfs, so trying to punish people for drawing their whole deck is less useful. In a matchup where you do want Hakkar, try to use Geosculptor Yip and Heavy Metal! when at 10+ armor: you'll have a 1 in 8 chance of Hakkar then.

Overall, the deck has allowed me to slowly climb in the rank 9-13 range. There are a lot of close matchups, for example against Spell Hunter. Don't expect it to rocket you toward legend, but you can complete quests with it without hurting your rank.

If your opponent is playing a control or combo deck, you can start building armor from turn 2. If your opponent is active on the board though, you have to carefully time your big armor upgrades, so you'll have 8+ armor when you play Heavy Metal! and Geosculptor Yip.

Compared to the first list I published, I put in Half-Time Scavenger. This allows you to set up armor gain by spending mana on an earlier turn, which is very useful in this deck.

I replaced Scaleworm with Militia Commander, since you typically only play these cards when you have something to rush into and in that case the Commander is more likely to survive into the next turn. Maybe the deck should use a second Commander to have a more consistent defense against aggro. The AoE cards don't really kick in until turn 6, when you can use Warpath three times or use Shield Block followed by Reckless Flurry, and sometimes you take too much damage before then.

Dragonmaw Scorcher is now a two-of. This card is working very well for me: the AoE is often useful, while it has high enough stats to frequently trade two for one.

Crowd Roaster performed so well that I included a second copy. It often takes care of two minions: one with the battlecry and another when it is traded into. It replaced Wyrmguard, since removing an enemy minion is more reliable than hoping a taunt stops it. Also the Roaster is more of a threat in matchups where you are the aggressor.

I replaced Dragon Roar by a second Bone Drake, since you get two dragons with either card (one being Bone Drake itself), but the Drake is more mana efficient, which matters for this deck. Also having another deathrattle makes it easier to get value from Da Undatakah early in the game.

This does put a lot cards in the 6-mana slot, which is generally not a good idea, but since Heavy Metal! is very situational, it's nice to have other 6-drops that can be reliably played on curve. I did remove one Gemstudded Golem to not overdo it.

Weapons Project is now a one-of. This card is both anti-weapon tech (it can replace weapons that are significantly better) and emergency armor gain. I'm not sold on the card yet: the weapon you give the opponent can sometimes help them a lot.

The list is probably still not optimal. One thing to look at is the removal: maybe include a second Smolderthorn Lancer?

If Spell Hunter remains popular, maybe a second copy of Bring It On! is useful.