Sanguine Sacrament
Most lifegain instants resolve and hit the graveyard, spent for good. This one goes to the exact bottom of your library instead, and that placement is the entire engine: no shuffle, no tutor, just a slow trip back through the deck until you draw it again, at which point another X buys another double-X of life. That structure reframes what the card is for. As a one-shot the rate is unremarkable; the math only sharpens in attrition, where the question is not "how much life now" but "how many times can I reset the clock before the opponent runs out of resources." It is built for the grind, a recurring life-tax against burn, aggression, and incidental drain rather than a single big swing. The bottom-of-library clause is also the leash on the effect: you cannot chain it for on-demand infinite life, because each replay demands a full lap through the deck plus the mana to recast. The cost of getting it back is the check on the payoff. Lifegain that returns to the bottom of your library is a slow valve rather than an engine you can crack open, and the design knows the difference between a card that wins games and one that simply refuses to lose them.
