Good man Christian Calcano snagged a GP win with this Snapcaster Mage beatdown deck: Creatures (12) Lands (23) Spells (25) Vapor Snag deserves a nod, though its not cracking the Top 50 list of blue cards
Mittens - Sassy Street Cat is a bodyguard, which means that she will be the target of all the opponent's challenges during their turn
For two mana, you now have a two-turn win on board, assuming your opponent doesnt destroy it immediately
Tiamat herself seems to have plenty of Constructed potential, especially with some way to reduce her cost or ramp up to it
This is right at home in life gain decks, where any amount of life you gain will be doubled
Two decks in particular showcased the power and flexibility of Energy counters, leading to such oppressive game states they required significant action from Magic 's Play Design team, in order to keep the Standard metagame under control