Ideally, it should actually look like a gentle curve that peaks relatively early (at the one- or two-cost columns) and then slopes downwards as the cost increases
Because flipping a card face-up is allowed even when a split second card is on the stack, he'd leverage the creature's morph ability to flip up and counter my split second spells
For (4) mana, it becomes a 3/3 creature with Vigilance and all creature types
All that said, the Loot, the Key to Everything decks on EDHrec are hardly running any land destruction
Save up your energy counters with Satya, and you'll be able to grow your attackers at an alarming rate.
Once players start dropping bombs, generally playing four mana per copy of those bombs are generally amazing.