There are three Avatar seasons
Old Stickfingers gets stronger the more creatures you have in your graveyard, but the ability to put creatures there just by playing your commander is the real draw here
Approach of the Second Sun As Luck Would Have It Azor's Elocutors Barren Glory Battle of Wits Biovisionary Call the Spirit Dragons Central Elevator // Promising Stairs Central Elevator // Promising Stairs Chance Encounter Coalition Victory Darksteel Reactor Doctor Doom, Unrivaled Duelists' Convocation International (playtest) Epic Struggle Felidar Sovereign Form of the Approach of the Second Sun Gallifrey Stands Halo Fountain Happily Ever After Hedron Alignment Helix Pinnacle Hellkite Tyrant Jace, Wielder of Mysteries Laboratory Maniac Laboratory Maniac Liliana's Contract Luck Bobblehead Mayael's Aria Maze's End Mechanized Production Mortal Combat Near-Death Experience Now I Know My ABC's Ramses, Assassin Lord Revel in Riches Shinryu, Transcendent Rival Simic Ascendancy Test of Endurance Thassa's Oracle The Cheese Stands Alone Triskaidekaphile Twenty-Toed Toad Wowzer, the Aspirational (playtest)
It then let any additional mana creatures left behind come out at no cost, and it got there in time to set up the cards with assisting and smooth out the deck, with the speed boost allowing you to invest in more expensive cards than could otherwise be justified
Most players want to keep a few key pieces and let the others die
Oh, and hd supercharges one creature a turn as well, meaning if you can give one of your souped up tokens evasion, you can dominate games quickly
