If you've already ripped open your preorders and are still looking for the cards below, it's probably going to save you money long term just buying the cards you need
Aang, Airbending Master Allied Teamwork Appa, Steadfast Guardian Captain's Claws Gather the White Lotus Gideon, Ally of Zendikar Hook Swords Invasion Reinforcements Iroh, Tea Master Jasmine Dragon Tea Shop Katara, Water Tribe's Hope Kyoshi Battle Fan Kyoshi Warriors Loyal Fire Sage Match the Odds Path to Redemption Pretending Poxbearers Retreat to Emeria Sokka and Suki Sokka, Tenacious Tactician Suki, Courageous Rescuer Suki, Kyoshi Warrior Sun Warriors Tolls of War Treetop Freedom Fighters Unified Front
You can engineer surprise one-shots to take opponents out of the game
Samis Curiousity This is as early as you can get a Lander
Why Baldur's Gate
In the right deck he'll be trivial to ultimate, even on the turn you play him - you just need to make a few treasures