Corren, Vehicle Inventor

Vehicles you control have a crew cost of 0.
Vehicles you control cost {1} less for each vehicle in your graveyard.
Sacrifice an artifact you control: search your library for an artifact card
with a converted mana cost, equal or higher than the destroyed artifact,
put that card in your hand. Shuffle your library.
Metalcraft: this card gains indestructible, and get +1/+1 for each vehicle in your hand.