Your cost starts at a reasonable , take Myojin of Cryptic Dreams for example, you save a bunch of mana and you turn your board into a Xerox machine
Then youve got Rampaging Baloths and Zendikars Roil
If you can manage to be the only other of two players left in the game, with a Spore Frog available to you, you're practically untouchable
However, theyre by no means necessary, so you should pretty much always take good, playable cards over them
If the creature that entered the battlefield leaves the battlefield before evolve tries to resolve, use its last known power and toughness to compare the stats
All-Out Assault Aurelia, the Warleader Aurelia, the Warleader Betor, Kin to All Brightfield Mustang Bumi, Unleashed Dazzling Theater // Prop Room Dazzling Theater // Prop Room Essence of Antiquity Fancy Footwork Full Throttle Great Train Heist Haunted Hellride Molten Note Mutinous Massacre North Pole Patrol Raph & Leo, Sibling Rivals Rustler Rampage Trystan's Command Unswerving Sloth Veteran Beastrider Virtue of Loyalty Watery Grasp Zealous Display