This is the newest aggressive deck in Standard, and boy does it pack a punch. Gruul creatures are sizable for the mana investment required, and we see in these games how important being able to curve out is. The deck is able to support the high-powered green creatures, and Goblin Chainwhirler, though it does require some concessions to the manabase. I have been impressed with what Gruul is capable of, and there are a few different ways to go about building it. This is my version:
The innovation of maindeck Kraul Harpooner is based off of the version Timothy Wu took to the Mythic Championship. Kraul Karpooner is known to be perhaps the best sideboard option against Mono-Blue Aggro, but that doesn't mean it needs to be exclusively a sideboard card. It is comparable to Zhur-Taa Goblin, and which one is better will be matchup dependant. The upside of potentially getting to kill an opposing creature with Kraul Harpooner is significant.
Some of the creature slots are set in stone, as you know there need to be four copies of Growth-Chamber Guardian. Sometimes you draw one late in a game and being able to have three more in your deck is huge. Considering the hoops we have gone through to fit Goblin Chainwhirler in the deck, of course there are four of them, and Gruul Spellbreaker is a bread and butter Gruul threat. Perhaps the most interesting spot on the curve is at five mana, though I have gone for Skarrgan Hellkite over Siege-Gang Commander.
You may be familiar with my love for Karn, Scion of Urza, as I tend to do well with decks that play the card. The one maindeck is a flex slot, and the mix of planeswalkers in the sideboard is also somewhat flexible. Still, I like the current mix. That being said I did make a sideboarding error when we faced off against another Gruul Aggro, when I had too many planeswalkers in on the draw. I should have known better! The games in this set were very swingy, which can happen with a deck like this that is reliant on curving out.
Thanks for reading,