Secondly, and more broadly: in an 'unknown' environment, particularly a post-large-set new environment, new decks are generally likely to do better than established decks, because it's much easier for the new decks to prepare for an established metagame than for the established decks to figure out which of the new decks are most critical to adapt to
Card Name Mana Cost Type Sorcery Rarity Rare rules Text Choose one -* Gain control of all creatures with power 4 or greater until end of turn
With cards like Scute Swarm, Field of the Dead, and Springheart Nantuko, this gets game ending incredibly quickly, so much so that people are already brewing cEDH decks around it
This card is single-handedly responsible for nearly obsoleting Darksteel Plate
#2: Inexorable Tide Proliferate can enable some of MTGs deadliest strategies, most notably Poison Counters