Sunbird's Invocation
The payoff scales with exactly the resource a big-mana deck is already manipulating: mana value. Every spell you cast from hand becomes a free look proportional to its size, so the six-drop that draws the reveal is also the one that opens the well six cards deep. Cast something expensive and you get to dig deep and cast a second spell for free; cast something cheap and you barely scratch the top. That asymmetry is the engine's discipline. It rewards a deck stacked with castable bombs and punishes one leaning on cheap interaction, since a two-mana spell reveals only two cards and frequently whiffs. The friction is real in two places: the reveal hits the top X cards rather than letting you pick, so you take what fortune deals, and you keep only one card from each reveal while the rest go to the bottom in random order. Note the ceiling that keeps this from spiraling: the free spell is cast from among the revealed cards, not from your hand, so it never re-triggers the enchantment. One cast, one free spell, no chain. What you get is a burst, not a loop: a single expensive cast that dumps a bomb onto the battlefield alongside the one you paid for. This is a build-around in the truest sense, inert without a top-heavy curve and enough acceleration to reach the expensive spell that starts the whole thing.
