These cards included the first commander to use the Energy mechanic: Dr
That is the best value you can get for a pack of marked cards

A Girl and Her Dogs (playtest) A Good Thing (playtest) Abbot of the Sacred Meeple (playtest) Abian, Luvion Usurper (playtest) Aggressive Crag (playtest) Alberix, the Trade Planet (playtest) All-Star Kicker (playtest) Anax and Cymede & Kynaios and Tiro (playtest) Animate Spell (playtest) Arcanum Things (playtest) Avacyn's Collar, the Symbol of Her Church (playtest) Banding Sliver (playtest) Baneslayer Aspirant (playtest) Barry's Land (playtest) Bear with Set's Mechanic (playtest) Bind (playtest) Biting Remark (playtest) Blood Poet (playtest) Blurry Visionary (playtest) Bolshack Dragon (playtest) Boltfire (playtest) Bombardment (playtest) Bone Rattler (playtest) Boulder Jockey (playtest) Brigid, Who's Seen Some Stuff (playtest) Bucket List (playtest) Built Bear (playtest) Buried Ogre (playtest) Call from the Grave (playtest) Can't Quite Recall (playtest) Catch of the Day (playtest) Celestine Cave Witch (playtest) Champion of the Hareish (playtest) Chatzuk, Mighty Guitarist (playtest) Chea, Friend to Maybe Too Many (playtest) Chimney Goyf (playtest) Chronobot (playtest) Cleaver Blow (playtest) Command the Chaff (playtest) Common Black Removal (playtest) Contest of Claws Contested Cliffs Contested Game Ball Contested War Zone Control Win Condition (playtest) Corrupted Key (playtest) Creepy Crawler (playtest) Cyclopean Titan (playtest) Dairy Cow (playtest) Defender of the Queue (playtest) Deputized Protester Do-Over (playtest) Domesticated Mammoth (playtest) Domesticated Watercourse (playtest) Don't Worry About It (playtest) Duelists' Convocation International (playtest) Dwarven Confluencer (playtest) Enchanted Prairie (playtest) Enchantmentize (playtest) Enroll in the Coalition (playtest) Essence of Ajani (playtest) Everlasting Lich (playtest) Evil Boros Charm (playtest) Experiment Five (playtest) Fatestitcher Fear of Failed Tests Feral Contest Fetching Garden (playtest) Field-Tested Frying Pan Five Kids in a Trenchcoat (playtest) Flanking Licid (playtest) Flavor Disaster (playtest)

When your next untap step rolls around, if the creature you exerted is untapped, nothing happens and the exertion cost you nothing
Postmortem Professor
Ideally, the temperature should be between 60-70F (15-24C), and the relative humidity should be around 40-50%