Love Song of Night and Day
A Saga's whole conceit is that it runs on rails: you cast it, it marches through I, II, III on a fixed schedule, and that sequence is a promise the card makes to both players. Read Ahead breaks the promise by letting you pick the entry point, and once you enter, the card still advances a chapter per turn from wherever you dropped in. That turns the ordering of these three chapters into the entire decision. Open at I when you want the burst now: you and a single target opponent each draw two, and the Bird arrives next turn, the counters the turn after. Open at II to lead with the flier and keep the counters chapter behind it. Or skip past I entirely and start at III when you only want to place two +1/+1 counters and sacrifice the Saga before it ever hands anyone cards. The first chapter is where the tension lives, because its draw is genuinely even: you feed an opponent two cards to draw two yourself, so opening there is a wager on whether you can afford to level the card economy this turn, and the answer flips with who is already ahead. The revealing bit of design is that the greedy, symmetric option is the one you have to consciously start on; skipping into the safer later chapters is a deliberate refusal to touch it, made at sorcery speed with the whole board in view.

