That's why the top players are top players - it's because they can be as consistent as possible, even though there's so much variance in the game
And then you can also do the dreaded bounce, block, bounce and stop an attack (You turn it from an aura to a dork, block, and then tap to make it an aura before damage is dealt, and the attacker is still blocked,)
When Mirror Room is on the battlefield, you can unlock Fractured Realm by paying the , so now both doors are unlocked and you have a 10-mana permanent on the battlefield
It pumps your board while shrinking your opponents creatures into irrelevance, and it can single-handedly shut down go-wide decks
Ulamog, the Ceaseless HungerUlamog, the Ceaseless Hunger lessens the downside by exiling permanents on casting, not on entering the battlefield