Mind's Dilation (Borderless) [Secret Lair Drop Series] Models Set: Bloomburrow Prerelease Promos Type:

Set: Bloomburrow Prerelease Promos Type: Enchantment — Class Rarity: Rare Cost: {1}{R} (Gain the next level as a sorcery to add its ability

In other words

Set: Ravnica Allegiance Prerelease Promos Type: Enchantment Rarity: Rare Cost: {3}{G} Whenever a nontoken creature enters the battlefield under your control

This expansion is not standalone

master of the Celestial Stampede

Mind's Dilation (Borderless) [Secret Lair Drop Series] Models Set: Bloomburrow Prerelease Promos Type:Set: Secret Lair Drop Series Type: Enchantment Rarity: Mythic Cost: {5}{U}{U} Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost. Depart yourself; one mind is too small a vessel.