Destiny Spinner Green has quite a few ways to protect itself from countermagic: Gaea's Herald and Prowling Serpopard protect your creatures, while Dosan the Falling Leaf and City of Solitude stop both countermagic and any other type of instants
Then the Black uncommon Heartless Act can destroy a dork with no counter
Any creature the player controls that couldnt be targeted by the original spell (due to shroud, protection abilities, targeting restrictions, or any other reason) is just ignored by Mirrorwing Dragons ability
Conqueror will obviously see plenty of Commander play, but its actually quite well-positioned for Standard too
Overall, Esper Pixie is a case study in just how resilient a Magic: The Gathering deck can be
In recent years, it has shown its age, with players well wise to the lures of the green mage