If you were playing fair, there was no way you could compete with that if the deck pulled it off and many games were won simply due to a willingness to play a card this powerful, allowing such decks to win long games they would otherwise be lost in
Frank Karsten from ChannelFireball has already figured out a 1-turn kill combo with Steam-Kin that goes like this: Mountain Simian Spirit Guide Runaway Steam-Kin 3x Pact of the Titan Goblin Bushwhacker / Reckless Bushwhacker Deal 20 damage If this proves to be that good, then Steam-Kin will jump in price as quickly as it can kill your opponents
You see, if you cast a spell that sets up an effect that happens "at end of turn" once you've past the start of the end-of-turn step, you can keep the results of that spell around until the next end-of-turn step
Other creatures in this deck can really make use of all these cards going into the graveyard
Panharmonicon has been a casual favorite since it was spoiled and now we have a more powerful version, as Yarok affects all permanent's enter-the-battlefield (ETB) triggers and not just artifacts and creatures, and it's stapled to a legendary creature in arguably the best three color combination