1-5 cards of rarity Rare of higher, 3-6 Uncommon cards, 5-8 Common cards, and 1 Land card (Traditional Foil Land replaces a Land in 20% of boosters)
The AoE cost may be a bit too steep, but since its an instant spell, the cost is totally justifiable
These adventures won't last forever
Much like how the original printing of Tarmogoyf would tease the introduction of the tribal card type, in true Marvel post-credits scene fashion Atraxa does the same for the new battle card type
The idea was to make the rarest cards in the set, which at the time were awarded the gold rare designation, easily distinguishable
Average the total mana spent to play it and unless it is under two we are looking pretty inefficient