Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Phoenix, Warden of Fire

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Rising Flames — Phoenix deals 2 damage to each opponent.
III — Flames of Rebirth — Return any number of target creature cards with total mana value 6 or less from your graveyard to the battlefield. Exile Phoenix, then return it to the battlefield (front face up).
Flying, lifelink

Joshua, Phoenix's Dominant

When Joshua enters, discard up to two cards, then draw that many cards.
{3}{R}{W}, {T}: Exile Joshua, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Joshua, Phoenix's Dominant // Phoenix, Warden of Fire

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Ravenous Chupacabra

When this creature enters, destroy target creature an opponent controls.

Ripples of Undeath

At the beginning of your first main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Aurelia, the Warleader

Flying, vigilance, haste
Whenever Aurelia attacks for the first time each turn, untap all creatures you control. After this phase, there is an additional combat phase.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Ashnod's Altar

Mystic Peak

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

Demon's Disciple

When this creature enters, each player sacrifices a creature or planeswalker of their choice.

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Sister Hospitaller

Medicus Ministorum — When this creature enters, return target creature card from your graveyard to the battlefield. You gain life equal to its mana value.

Blade Historian

Attacking creatures you control have double strike.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Fear of Missing Out

When this creature enters, discard a card, then draw a card.
Delirium — Whenever this creature attacks for the first time each turn, if there are four or more card types among cards in your graveyard, untap target creature. After this phase, there is an additional combat phase.

Priest of Forgotten Gods

{T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature of their choice. You add {B}{B} and draw a card.

Redemption Choir

Lifelink
Coven — Whenever this creature enters or attacks, if you control three or more creatures with different powers, return target permanent card with mana value 3 or less from your graveyard to the battlefield.

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

Alesha, Who Laughs at Fate

First strike
Whenever Alesha attacks, put a +1/+1 counter on it.
Raid — At the beginning of your end step, if you attacked this turn, return target creature card with mana value less than or equal to Alesha's power from your graveyard to the battlefield.

Loran of the Third Path

Vigilance
When Loran enters, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.