A drop that includes three board wipes in Day of Judgment, Star of Extinction, and Toxic Deluge would already be frightening, but adding in an extra turn spell in Temporal Extortion, and a way to exile key cards from your opponents' decks with Praetor's Grasp makes this by far the meanest Secret Lair drop we've ever seen
Donald Duck, Musketeers promo card was printed as part of a convention giveaway
So both of those have limitations, and this does as well
Spend two mana to turn everything in to a base 2/2, swing with everything and get the Duskana boost, then spend more mana to activate Mirror Entity again to make everything much bigger
It's easy to see this is very strong in a dedicated Humans deck
Each transforming double-faced card (or TDFC) has two card faces