Here are some less expensive alternatives for key cards in your deck: Creatures Enchantments Artifacts Instant/Sorceries Lands
When it comes to "win percentage" the Command Zone did 2 podcasts dedicated to figuring out which color was the strongest (their video here) and as you can see at 23:44 minutes in, they ran a poll where White is the 2nd weakest on the list
Avatar Aang / Aang, Master of Elements is a Mythic, Legendary Creature - Human Avatar Ally / Legendary Creature - Avatar Ally card from the Magic The Gathering set Avatar The Last Airbender (MTGSC-TLA-0363)
In Magic: The Gathering , your graveyard is one of your most important resources
The first effect will potentially lock either player out of a turn, and the second will guarantee it to your opponent
negate its effects (until the end of this turn), then banish the top 3 cards of your opponent's Deck