This new mechanic is quite simple at first, as when players play a card that says, "Start your engines," they, literally, start their engines
While the gameplay of face-down cards is always extremely memorable and fun in Limited, their mana-intensive setup and complex rules seemed to belong to a long-past era of Magic design
Lead designer Mark Rosewater rated it 9/10 on his influential Storm Scale, indicating a mechanic which would require a minor miracle to ever be used in a new Standard set
Id consider Entomb and Buried Alive the first two slots for this, but I also really like Final Parting and Jarads Orders, since both replace themselves with a card in your hand
No extra fees
Alternatively, you can cheat this mana cost through the use of mechanics like proliferate in order to provide additional hatchling counters without actually paying for them