Trash for Treasure: Another 'discard an artifact to recover a better artifact' card
back to your deck, Shachi & Penguins ability can help you ramp back up to a healthy board state to cheat out even more four-cost characters
Though these are all undeniably exciting, the rarest and most sought after cards will be the serialized foil cards in the Collector Boosters
Greasefang, Okiba Boss cares about having vehicles in your graveyard, which makes me think of a porte-manteau of motor pool and cesspool. I like the theming here: You cast your vehicles, they exist on the battlefield, they die in combat, Greasefang brings them back, they can come back to your hand if they survive
They'll work just like avatars currently do, only now there are more of them