Tergrid's Shadow Each player sacs two creatures is potentially a huge effect, and 2 and 4 means it can come out relatively quickly, essentially generally resetting the board and will frequently clear out commanders since players will often have 1 utility creature to protect vs a single sacrifice effect, but not two, though your mileage may vary depending on your meta
While red has very few nontargeted removal options to get rid of a Priest, black can run Diabolic Edict, Innocent Blood, and Chainer's Edict just fine
Since the sample size is small, I would look for additional data to support selling Kaladesh booster boxes and buying Aether Revolt booster boxes
Most extra-turn spells cost five mana or more, which explains why its such a massive outlier in power
8 Sergeant Tibbs: Courageous Cat The Sergeant Tibbs card in Disney Lorcana isn't one of the showiest, but it does an excellent job of recapturing the raggedly sketchy look of the animation in 101 Dalmations