Having a Doubling Season on a stick that's also a legendary stick opens so many options that the mind is boggled
It seems unplayable outside of some kind of EDH deck that runs red in a blink shell (an idea that gets better and better with each release!)
For example, Fabled Passage is another fetchland that can only grab basic lands, but it's much better since there's at least a chance the land could enter untapped
These holos were the original chase cards, and their tactile difference from regular cards made them instantly recognizable
And since revealing it doesnt get rid of it, you can do so over and over again
It's part of a combo known as the 'Pickles lock,' wherein Brine Elemental is the 'Pickles' and Vesuvan Shapeshifter is the combo piece that copies Brine Elemental turn after turn, preventing your opponents from untapping