Mechanically, there's no particular quality that separates Elder Dragons from the best MTG dragons like Ur-Dragon - they're just a particular flavour of powerful scaly lizard, though in the lore the first five elders were said to be as strong as planeswalkers
That alone is enough to justify the 2 mana cost, and it already brings back memories of Stoneforge Mystic and how it became an absolute menace in games
Alisaie Leveilleur + Alphinaud Leveilleur These partner with commanders have great synergy
The promo card, Moana, Adventurer of Land and Sea, is a sneak peek card from a future Disney Lorcana TCG set
Thalia, Guardian of Thraben Thalia, Guardian of Thraben is a cheap and taxing creature for your opponent to deal with
It gives each of them a power and toughness boost equal to the number of colors they have, which turns efficient threats into unstoppable monsters