Fling Colossus (Standard)

Built with the idea of flinging colossus. Ideally would play key to the city turn 2. Discard colossus with key or tormenting voice. Refurbish colossus turn 4. On turn 5 make colossus unblock-able with key, swing for 10 then fling for the win. Alternatively if you don't have a colossus you can play vehicles and make them threats with siege modification and/or peace walker colossus's ability. Creatures are meant to be pilots and draw/scry sources. For a possible turn 4 kill: if your opponent doesn't have fliers you can play heart of kiren turn 2, seige modification it turn 3 swing for 7, turn 4 swing for 7 fling. Sideboard has all the removal, crook of condemnation for graveyard decks and it makes colossus cheaper, hour of devastation if the board state gets out of hand, cast out for all around purposes, built to last if your opponent brings in artifact hate, and abrade for some artifact hate/removal against your opponent. Could easily add a better mana base, however I was trying to keep the budget for the deck low. Feedback would be appreciated.