Ancient Lumberknot Arcades, the Strategist Assault Formation Baldin, Century Herdmaster Bark of Doran Bedrock Tortoise Belligerent Brontodon Bill the Pony Doran, the Siege Tower Felothar the Steadfast Gauntlets of Light High Alert Huatli, the Sun's Heart Plagon, Lord of the Beach Rasaad yn Bashir Solid Footing Streetwise Negotiator Tapestry Warden The Great Forest Treefolk Umbra Walking Bulwark Weight Advantage
Collectors sometimes chase very specific cards, especially misprints
Mass of Mysteries is Dance of the Elements alternate Commander, and is a far more aggressive legendary than Ashling
Its advantage compared to the other options is in the third chapter, which works as a wincondition since it offers Trample to the creature, in addition to the power increase equal to the number of lands in exchange, it requires a turn to do what Lumra, Bellow of the Woods does when it comes into play