Its a 2/1 body for just 1 mana that will totally screw with Tarmogoyf and Snapcaster Mage (2 of the most played cards in the format)
Other popular pillows include Ghostly Prison, Propaganda, and their ilk, making it difficult for those go wide decks to attack
By rushing out and dealing combat damage, Rankle can force each player to sacrifice a creature, among other effects (including Eldraines infamous surplus of card draw) to sweeten the deal
This is an amazingly useful counter card, and great for stopping a whole range of things
Unfortunately, its complexity is also its downfall at times, as it can prevent new players from becoming interested in the game because of the high barrier to entry
"Dragon Treasure"), and its equip target no longer meets those parameters, the Equip Card is destroyed