Geyadrone Dihada can't be targeted, dealt damage, or enchanted by any permanent with a corruption counter on it
Cards like Doubling Season, Parallel Lives, and Unbound Flourishing all increase The Goose Mother's abilities, giving you a massively powerful creature to rush down your opponents
You get three copies of Friends on the Other Side which is Amethysts best draw tool allowing you to snag two cards from the top of your deck
Setup and teardown is quick and simple with parts that slide together
While it can be dealt with cleanly by a Swords to Plowshares, assuming you managed to hit a creature or planeswalker of theirs, they would have paid three cards (Swords, discarded card and creature/planeswalker) for your one (Entomb/Faithless Looting and reanimation spell offset by drawing a card)
That all changed earlier today when WOTC gave us our first look at the face commander for each of the precons