The Raven Man [Dominaria United Prerelease Promos] Sliver Mutant Set: Rivals of Ixalan Prerelease

Set: Rivals of Ixalan Prerelease Promos Type: Creature — Dinosaur Rarity: Rare Cost: {2}{G} Ascend (If you control ten or more permanents

Set: Throne of Eldraine Type: Enchantment Rarity: Rare Cost: {1}{W}{B} Whenever a Knight you control attacks

Set: Masters 25 Type: Artifact — Equipment Rarity: Uncommon Cost: {2} Equipped creature has hexproof and haste

Thus The Grand Evolution began

This plays very similarly to the flood mechanic in the Atlantis scenario from the Atlantis and Das Buch scenario packs

The Raven Man [Dominaria United Prerelease Promos] Sliver Mutant Set: Rivals of Ixalan PrereleaseSet: Dominaria United Prerelease Promos Type: Legendary Creature Human Wizard Rarity: Rare Cost: {1}{B} At the beginning of each end step, if a player discarded a card this turn, create a 1 1 black Bird creature token with flying and "This creature can't block." {3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.