Meet Naga Fleshcrafter This blue, four-mana Snake Shapeshifter has the ability to copy any creature on the battlefield as it enters, making it a versatile card that adapts to both your and your opponents situations
Here are the Top Ten Super Rare and Legendary cards from its first set, The First Chapter
You pretty much can only use Krovikan Mist with illusion-focused decks, but it should give you decent value there
You can find copies of this card for a bit cheaper but, for the most part, this is what most traditional variant Overlord of the Boilerbilges go for
For instance, you could make the Stage 2 Metal Klinklang and the Stage 2 Lightning Eelektross
The Giant deck probably leans more heavily on Changelings than any of the other tribal archetypes since Kithkin Greatheart, Blind-Spot Giant, and Crush Underfoot are so heavily reliant on having the right creature type to take advantage of them