The Day of the Doctor
The three identical impulse-draw chapters are the whole engine here: three consecutive digs through your library that stop on the first legendary card and hand it to you, playable only while the Saga sits on the battlefield. Note that word: play, not cast. A legendary land you dig into can be dropped straight onto the battlefield, so the dig rewards any legend density, not just spells. That leash is the interesting part. You are not just filtering; you are on a lease, and each legend you unearth has to be deployed before the clock runs out, so the card rewards decks stuffed with legends (the higher the density, the shallower each dig) and punishes hoarding. Then chapter IV arrives as one of the more theatrical payoffs a Saga has ever offered: a mass exile of every creature that is not among up to three Doctors you choose on the battlefield, bought with thirteen damage to your own life total. The number is not arbitrary flavor dressing; it is the actual cost you weigh against the board it clears, and the tribal restriction locks the finale to Doctors already in play rather than any legend you managed to find. The two halves are wired together: three turns of digging builds toward a board you then get to protect from your own reset. It is a rare Saga that asks you to plan three turns of resource generation and then decides whether the final chapter is a triumph or a self-inflicted wound.
