Me: Official answer: Seven just felt right
Scientists Academy Elite Academy Loremaster Academy Wall Accumulated Knowledge Acquisition Octopus Aeon Chronicler Aether Channeler Aether Syphon Airborne Aid Alandra, Sky Dreamer Alchemist's Apprentice All-Seeing Arbiter Alphinaud Leveilleur Amass the Components An Unearthly Child Ancestral Reminiscence Aphetto Runecaster April O'Neil, Hacktivist April O'Neil, Live on the Scene April, Reporter of the Weird Aquitect's Will Arcane Denial Arcane Investigator Arcane Subtraction Archive Haunt Archivist Archmage Ascension Archmage Emeritus Archmage of Runes Argent Mutation Arrester's Admonition Artful Looter Artificer's Epiphany Artistic Refusal Ascendant Spirit Assassin Gauntlet Astral Wingspan Astrologian's Planisphere Atemsis, All-Seeing Atlantean Cavalry Atlantean Skirmisher Attuma, Atlantean Warlord Aura Finesse Aven Fisher Avian Oddity Azami, Lady of Scrolls Azure Mage B.O.B
Let's have a look at the top 10 most valuable cards from the set to find out
It requires no additional mana other than the initial paid casting cost, but getting BBB mana is often a steep requirement, outside of Dark Ritual
I'm honestly surprised it worked within the rules
This list will lay out just that
