Legendary Creature — Angel

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Avacyn, the Purifier

From the Vault: Transform

Shadows Over Innistrad Checklist 2

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn

Legendary Land

(Transforms from Arguel's Blood Fast.)
{T}: Add {B}.
{T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Temple of Aclazotz

Ixalan Checklist

High Marshal Arguel

Legendary Enchantment

{1}{B}, Pay 2 life: Draw a card.
At the beginning of your upkeep, if you have 5 or less life, you may transform Arguel's Blood Fast.

Arguel's Blood Fast

Legendary Planeswalker — Arlinn

+1: Creatures you control get +1/+1 and gain trample until end of turn.
−1: Arlinn deals 3 damage to any target. Transform Arlinn.
−6: You get an emblem with "Creatures you control have haste and '{T}: This creature deals damage equal to its power to any target.'"

Arlinn, Embraced by the Moon

Arlinn, Embraced by the Moon Emblem

Wolf

+1: Until end of turn, up to one target creature gets +2/+2 and gains vigilance and haste.
0: Create a 2/2 green Wolf creature token. Transform Arlinn Kord.

Arlinn Kord

Creature — Vampire

Flying
Other Vampire creatures you control get +2/+2.
{T}: Create a 2/2 black Vampire creature token with flying.

Lord of Lineage

Vampire

Innistrad Checklist

Flying
{T}: Create a 2/2 black Vampire creature token with flying.
{B}: Transform this creature. Activate only if you control five or more Vampires.

Bloodline Keeper

Legendary Creature — Eldrazi Angel

Meld part of Brisela, Voice of Nightmares

Eldritch Moon Checklist

Brisela, Voice of Nightmares

Gisela, the Broken Blade

Legendary Creature — Angel Horror

When you cast this spell, you may return target Angel or Human creature card from your graveyard to the battlefield.
Flying, vigilance
(Melds with Gisela, the Broken Blade.)

Bruna, the Fading Light

Flying, first strike, vigilance, lifelink
Your opponents can't cast spells with mana value 3 or less.

Legendary Planeswalker — Chandra

+1: Chandra deals 2 damage to target player or planeswalker.
−2: Chandra deals 2 damage to target creature.
−7: Chandra deals 6 damage to each opponent. Each player dealt damage this way gets an emblem with "At the beginning of your upkeep, this emblem deals 3 damage to you."

Chandra, Roaring Flame

Magic Origins Checklist

Chandra, Roaring Flame Emblem

Legendary Creature — Human Shaman

Whenever you cast a red spell, untap Chandra.
{T}: Chandra deals 1 damage to target player or planeswalker. If Chandra has dealt 3 or more damage this turn, exile her, then return her to the battlefield transformed under her owner's control.

Chandra, Fire of Kaladesh

Creature — Human Insect

Insectile Aberration

Creature — Human Wizard

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform this creature.

Delver of Secrets

Legendary Creature — Demon

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Withengar Unbound

Dark Ascension Checklist

Legendary Artifact — Equipment

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, then transform it.
Equip {1}

Elbrus, the Binding Blade

Legendary Planeswalker — Garruk

+1: Create a 1/1 black Wolf creature token with deathtouch.
−1: Sacrifice a creature. If you do, search your library for a creature card, reveal it, put it into your hand, then shuffle.
−3: Creatures you control gain trample and get +X/+X until end of turn, where X is the number of creature cards in your graveyard.

Garruk, the Veil-Cursed

When Garruk has two or fewer loyalty counters on him, transform him.
0: Garruk deals 3 damage to target creature. That creature deals damage equal to its power to him.
0: Create a 2/2 green Wolf creature token.

Garruk Relentless

Flying, first strike, lifelink
At the beginning of your end step, if you both own and control Gisela and a creature named Bruna, the Fading Light, exile them, then meld them into Brisela, Voice of Nightmares.

Creature — Werewolf

Trample
Whenever this creature transforms into Ravager of the Fells, it deals 2 damage to target opponent or planeswalker and 2 damage to up to one target creature that player or that planeswalker's controller controls.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.

Ravager of the Fells

Creature — Human Werewolf

Whenever this creature enters or transforms into Huntmaster of the Fells, create a 2/2 green Wolf creature token and you gain 2 life.
At the beginning of each upkeep, if no spells were cast last turn, transform this creature.

Huntmaster of the Fells

Legendary Planeswalker — Jace

+1: Up to one target creature gets -2/-0 until your next turn.
−3: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead.
−9: You get an emblem with "Whenever you cast a spell, target opponent mills five cards."

Jace, Telepath Unbound

Jace, Telepath Unbound Emblem

Legendary Creature — Human Wizard

{T}: Draw a card, then discard a card. If there are five or more cards in your graveyard, exile Jace, then return him to the battlefield transformed under his owner's control.

Jace, Vryn's Prodigy

Legendary Planeswalker — Gideon

+2: Up to one target creature an opponent controls attacks Gideon during its controller's next turn if able.
+1: Until your next turn, target creature gains indestructible. Untap that creature.
0: Until end of turn, Gideon becomes a 4/4 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.

Gideon, Battle-Forged

Legendary Creature — Human Soldier

At end of combat, if Kytheon and at least two other creatures attacked this combat, exile Kytheon, then return him to the battlefield transformed under his owner's control.
{2}{W}: Kytheon gains indestructible until end of turn.

Kytheon, Hero of Akros

Legendary Planeswalker — Liliana

+2: Each player discards a card.
−X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.
−8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Liliana, Defiant Necromancer

Liliana, Defiant Necromancer Emblem

Zombie

Legendary Creature — Human Cleric

Lifelink
Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

Liliana, Heretical Healer

Legendary Planeswalker — Nissa

+1: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.
−2: Create Ashaya, the Awoken World, a legendary 4/4 green Elemental creature token.
−7: Untap up to six target lands. They become 6/6 Elemental creatures. They're still lands.

Nissa, Sage Animist

Ashaya, the Awoken World

Legendary Creature — Elf Scout

When Nissa enters, you may search your library for a basic Forest card, reveal it, put it into your hand, then shuffle.
Whenever a land you control enters, if you control seven or more lands, exile Nissa, then return her to the battlefield transformed under her owner's control.