Summon: Knights of Round

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after V.)
I, II, III, IV — Create three 2/2 white Knight creature tokens.
V — Ultimate End — Other creatures you control get +2/+2 until end of turn. Put an indestructible counter on each of them.
Indestructible

Knight

Peri Brown

The first historic spell you cast each turn has convoke. (Your creatures can help cast it. Each creature you tap while casting it pays for {1} or one mana of that creature's color.)
Doctor's companion (You can have two commanders if the other is the Doctor.)

Banish to Another Universe

Affinity for historic permanents (This spell costs {1} less to cast for each artifact, legendary, and/or Saga permanent you control.)
When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

An Unearthly Child

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II, III — Reveal cards from the top of your library until you reveal a Doctor card, a card with doctor's companion, or a Vehicle card. Put that card into your hand and the rest on the bottom of your library in a random order.

Karn's Temporal Sundering

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Target player takes an extra turn after this one. Return up to one target nonland permanent to its owner's hand. Exile Karn's Temporal Sundering.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Ian Chesterton

Science Teacher — Each Saga spell you cast has replicate. The replicate cost is equal to its mana cost. (When you cast that Saga, copy it for each time you paid its replicate cost. Copies of Saga spells become tokens.)
Doctor's companion (You can have two commanders if the other is the Doctor.)

Traverse Eternity

Draw cards equal to the greatest mana value among historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)

The Night of the Doctor

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after II.)
I — Destroy all creatures.
II — Return target legendary creature card from your graveyard to the battlefield. Put your choice of a first strike, vigilance, or lifelink counter on it.

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Plains

Monumental Henge

This land enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Look at the top five cards of your library. You may reveal a historic card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. (Artifacts, legendaries, and Sagas are historic.)

History of Benalia

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Create a 2/2 white Knight creature token with vigilance.
III — Knights you control get +2/+1 until end of turn.

Island

Barbara Wright

History Teacher — Sagas you control have read ahead. (As a Saga enters, choose a chapter and start with that many lore counters. Skipped chapters don't trigger.)
Doctor's companion (You can have two commanders if the other is the Doctor.)