I reached legend this season with my aggro warlock deck. Since there is a lack of aggro guides and it’s rare to see someone stream aggro decks, I thought I can give you some tips.
I used this deck from rank 20 to legend and still have success with it in the legend ranks.
This is not one of the usual rush decks with Wolfriders and Arcane Golems, but revolves around board control and trading most of the time.
Build a strong board presence and keep it while tapping for your finisher. The win condition ususally is Leeroy + 1 or 2 Power Overwhelmings + Soulfire dealing 14-18 damage for only 6 mana. Your opponent should be in lethal range by the time you get these combo pieces. The key is to plan ahead how much damage you can deal in your next few turns and how you can answer possible threats while keeping board presence and playing around AoE.
About some of the card choices:
There are no Doomguards in this deck, because you don’t want to discard pieces of your finisher. Don’t use Soulfire early unless you really have to for the same reason. I picked Leper Gnomes over the Flame Imps, because the three damage from the Flame Imp are a huge drawback in the late game while they are easily removed. The two damage to your opponent from the Leper Gnomes are guaranteed and Flame Imps are not necessary in the early game, which already is really strong.
The Hellfire helps if your opponent manages to gain board control and also pushes 3 damage to the face through taunts. Make sure to have one or two minions to repopulate the board the same round after you use Hellfire.
Always keep Argent Squire, Voidwalker and Leper Gnomes. It’s best to follow up with buffing them with Dire Wolves or Abusive Sergeants to trade them with your opponents minions. Keep a Mortal Coil if you expect aggro.
Druids and control warrior are the hardest matchups. They are not unbeatable, but you will probably use one of the Power Overwhelmings or Soulfires in the midgame to remain board control. Hellfire also helps a lot against these two. The Owls usually silence the bigger taunts.
- Miracle Rogue: Try to bait their removals. You may keep an Owl in your starting hand when going first to counter Van Cleeve.
- Priest: Try to keep the Argent Commanders behind a taunt and don’t buff them with the Cleric or Defender of Argus.
- Hunter: Use the Power Overwhelmings to push damage through Explosive Traps. Tap carefully.
- Zoo: It’s all about board control. An early Soulfire helps to keep up the tempo. You usually have won if you draw the Hellfire.
- Handlock: Owl + Mortail Coil their Drakes. The mountain giant forces you to use one of the Power Overwhelmings. Keep their hero live above 15 and burst finish.
- Paladin: If aggro -> same as zoo. If control, keep an Owl for Tirion.
- Mage: Buff your minions health and tap carefully.
- Shaman: Kill their totems. You may keep the Hellfire in your starting hand.
If you don’t have Leeroy, replace him with an Arcane Golem, but keep it in your hand as the finisher. I won more games with 2 or more damage overkill than I lost due to missing two damage, so the 2 attack difference between Leeroy and Arcane Golem don’t matter that much.