Proliferate cards, like Cankerbloom and Yawgmoth, Thran Physician, help a ton here too, giving you even more experience to work with
To determine the total cost of a spell, start with the mana cost or alternative cost youre paying, add any cost increases, then apply any cost reductions
Ultimate isn't really a stone, but don't tell it I said that
One of designer Gavin Verhey's playtest cards at a recent Magic convention also let you cast all your creature cards as Colossal Dreadmaws - a precursor for Dino DNA's release
Rarity in Disney Lorcana is basically divided into five ranks, with Common, Uncommon, Rare, Super Rare and Legendary cards all having different distributions that make each rank more attractive than the last