Only being able to use it as a Sorcery makes it doubly bad
Day of Judgment Herald of Eternal Dawn Kaito, Cunning Infiltrator Think Twice Bloodthirsty Conqueror Twinflame Tyrant Doubling Season Llanowar Elves Muldrotha, the Gravetide Progenitus A total of 51 cards were given anime treatments specifically for the Foundations Jumpstart set, including reprints like Adeline, Resplendent Cathar, Kodama of the West Tree, and one of Magic's best demons, Vilis, Broker of Blood, as well as new cards like Evereth, Viceroy of Plunder and Dionus, Elvish Archdruid
While it doesn't have the same years of history or rows of rare cards behind it, the price of one Disney Lorcana card shows that it has already managed to create an aggressive resale market
If the copied creature is copying something else, then Mockingbird enters as whatever that creature copied, with the noted exceptions
New rarity
Declaration in Stone is going for $15, an incredible value for a rare kill spell in this format