The absolute power level of Sphinxs Revelation as in how strong it is as a card in a vacuum is through the roof, but what about contextually in this format at this time
(Choose a creature with the least toughness among creatures you control and put X +1/+1 counters on it.) To determine the number of differently named artifact tokens you control, count each artifact token you control once, but only if its English name isn't exactly the same as another artifact token you've already counted this way
WWWW - Blizzard (50) Effect: Flip a coin
The condition itself becomes the new source of rarity , causing the price to skyrocket
Its ability to draw a card while untapping lands is pretty powerful on an empty board, allowing you to hold up counters or removal on the next turn while you deal with something using its -3 right away
But, the sideboarded games played out much differentlybetterand I was able to apply pressure at all the right points with judicious use of Thoughtseize, Duress, and Erebos