Mirari's Wake

Doubling your entire manabase from a single five-mana enchantment was, in its era, a quietly absurd proposition: most ramp of the period worked one rock or one creature at a time, and here was a payoff that scaled with every land you controlled. The doubling is a triggered ability, firing each time you tap a land for mana and adding one more of the same type the land produced, which matters: it answers to nothing on the stack and feeds colored-intensive top-ends without demanding perfect fixing. The anthem half is almost incidental, a green-white throwaway to justify the second color, but the mana engine is what built an archetype. A board of six lands becomes twelve mana the following turn, and the card doesn't so much ask for a payoff as dare you to find one big enough to deserve it. That gap between mana produced and mana spendable is where the deckbuilding tension lives, and overshooting it is the failure mode the design invites. What makes it hold up is that the effect is loud and slow. It costs real mana, it does nothing to protect itself, and it telegraphs a haymaker a full turn early. Later doublers tend to be cheaper or stapled to a body; this one stays the platonic version because it sits in the open, generates obscene value, and trusts whatever you've built around it to spend the surplus before the table answers it.