Birth of the Imperium

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/2 white Astartes Warrior creature token with vigilance for each opponent you have.
II — Each opponent sacrifices a creature of their choice.
III — Draw two cards for each opponent who controls fewer creatures than you.

Battle of Frost and Fire

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Battle of Frost and Fire deals 4 damage to each non-Giant creature and each planeswalker.
II — Scry 3.
III — Whenever you cast a spell with mana value 5 or greater this turn, draw two cards, then discard a card.

Battle at the Helvault

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — For each player, exile up to one target non-Saga, nonland permanent that player controls until Battle at the Helvault leaves the battlefield.
III — Create Avacyn, a legendary 8/8 white Angel creature token with flying, vigilance, and indestructible.

Likeness of the Seeker

Whenever Likeness of the Seeker becomes blocked, untap up to three lands you control.

Azusa's Many Journeys

(As this Saga enters and after your draw step, add a lore counter.)
I — You may play an additional land this turn.
II — You gain 3 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.