This is similar to my philosophy on bans in Constructed, and the importance of removing problematic cards to expand the relevant percentage of the card pool
The symbols at the bottom of each card indicate rarity level
Angler's Shield Armorcraft Judge Become the Avalanche Biorganic Carapace Blessing of Frost Cloud, Ex-SOLDIER Collective Unconscious Duskana, the Rage Mother Freyalise, Llanowar's Fury Gamma Grotesque Goliath, Mass Manipulator Heirloom Epic Infinite Guideline Station Inspiring Call Mouth // Feed Mouth // Feed Night of the Flying Merfolk (playtest) Plagon, Lord of the Beach Pol Jamaar, Illusionist Regal Force Shaman of the Great Hunt Shamanic Revelation Slate of Ancestry The Horus Heresy Tishana, Voice of Thunder Titan of Littjara Titan of Littjara Vivien's Stampede Voja, Jaws of the Conclave Winged Portent
Nine more cards got an Art Deco showcase exclusive to Collector Boosters
Mark Rosewater scores it a 4 on the storm scale, meaning it's likely to come back
Whenever an opponent casts their second spell each turn, you create a Treasure token