Gideon, Champion of Justice

+1: Put a loyalty counter on Gideon, Champion of Justice for each creature target opponent controls.
0: Until end of turn, Gideon, Champion of Justice becomes a Human Soldier creature with power and toughness each equal to the number of loyalty counters on him and gains indestructible. He's still a planeswalker. Prevent all damage that would be dealt to him this turn.
−15: Exile all other permanents.

Suture Priest

Whenever another creature enters the battlefield under your control, you may gain 1 life.
Whenever a creature enters the battlefield under an opponent's control, you may have that player lose 1 life.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Island

Jace's Archivist

{U}, {T}: Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Rivendell

Rivendell enters the battlefield tapped unless you control a legendary creature.
{T}: Add {U}.
{1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Mercy Killing

Target creature's controller sacrifices it, then creates X 1/1 green and white Elf Warrior creature tokens, where X is that creature's power.

Sphere of Safety

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of enchantments you control.

Alliance of Arms

Join forces — Starting with you, each player may pay any amount of mana. Each player creates X 1/1 white Soldier creature tokens, where X is the total amount of mana paid this way.

Keep Watch

Unwind

Counter target noncreature spell. Untap up to three lands.

Orim's Prayer

Whenever one or more creatures attack you, you gain 1 life for each attacking creature.

Custodi Soulbinders

Custodi Soulbinders enters the battlefield with X +1/+1 counters on it, where X is the number of other creatures on the battlefield.
{2}{W}, Remove a +1/+1 counter from Custodi Soulbinders: Create a 1/1 white Spirit creature token with flying.

Genesis Chamber

Whenever a nontoken creature enters the battlefield, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Rewind

Counter target spell. Untap up to four lands.

Detention Sphere

When Detention Sphere enters the battlefield, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.
When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Declaration in Stone

Exile target creature and all other creatures its controller controls with the same name as that creature. That player investigates for each nontoken creature exiled this way.

Tragic Arrogance

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Ezuri's Predation

For each creature your opponents control, create a 4/4 green Phyrexian Beast creature token. Each of those tokens fights a different one of those creatures.

Simic Signet

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Plains

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Flurry of Wings

Create X 1/1 white Bird Soldier creature tokens with flying, where X is the number of attacking creatures.

Kavu Predator

Trample
Whenever an opponent gains life, put that many +1/+1 counters on Kavu Predator.

Akroan Horse

Defender
When Akroan Horse enters the battlefield, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Krosan Verge

Krosan Verge enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Krosan Verge: Search your library for a Forest card and a Plains card, put them onto the battlefield tapped, then shuffle.

Selvala, Explorer Returned

Parley — {T}: Each player reveals the top card of their library. For each nonland card revealed this way, add {G} and you gain 1 life. Then each player draws a card.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Angel's Trumpet

All creatures have vigilance.
At the beginning of each player's end step, tap all untapped creatures that player controls that didn't attack this turn. Angel's Trumpet deals damage to the player equal to the number of creatures tapped this way.

Twiddle

You may tap or untap target artifact, creature, or land.

Mirrorweave

Each other creature becomes a copy of target nonlegendary creature until end of turn.

Crown of Doom

Whenever a creature attacks you or a planeswalker you control, it gets +2/+0 until end of turn.
{2}: Target player other than Crown of Doom's owner gains control of it. Activate only during your turn.

Theft of Dreams

Draw a card for each tapped creature target opponent controls.

Sea of Clouds

Sea of Clouds enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Island Sanctuary

If you would draw a card during your draw step, instead you may skip that draw. If you do, until your next turn, you can't be attacked except by creatures with flying and/or islandwalk.

Sol Ring

Echoing Courage

Target creature and all other creatures with the same name as that creature get +2/+2 until end of turn.

Getting

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Forest

Briar Patch

Whenever a creature attacks you, it gets -1/-0 until end of turn.

Call

Create four 1/1 white Bird creature tokens with flying.
Fuse (You may cast one or both halves of this card from your hand.)

Beck

Whenever a creature enters the battlefield this turn, you may draw a card.
Fuse (You may cast one or both halves of this card from your hand.)

Beck // Call

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Axis of Mortality

At the beginning of your upkeep, you may have two target players exchange life totals.

Tamiyo, the Moon Sage

+1: Tap target permanent. It doesn't untap during its controller's next untap step.
−2: Draw a card for each tapped creature target player controls.
−8: You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand."

Borrowing 100,000 Arrows

Selesnya Signet

Azorius Chancery

Azorius Chancery enters the battlefield tapped.
When Azorius Chancery enters the battlefield, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Nacatl War-Pride

Nacatl War-Pride must be blocked by exactly one creature if able.
Whenever Nacatl War-Pride attacks, create X tokens that are copies of Nacatl War-Pride and that are tapped and attacking, where X is the number of creatures defending player controls. Exile the tokens at the beginning of the next end step.

Reverence

Creatures with power 2 or less can't attack you.

Lost Vale

(Transforms from Dowsing Dagger.)
{T}: Add three mana of any one color.

Dowsing Dagger

When Dowsing Dagger enters the battlefield, target opponent creates two 0/2 green Plant creature tokens with defender.
Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a player, you may transform Dowsing Dagger.
Equip {2}

Dowsing Dagger // Lost Vale

Sylvan Offering

Choose an opponent. You and that player each create an X/X green Treefolk creature token.
Choose an opponent. You and that player each create X 1/1 green Elf Warrior creature tokens.

Imaginary Threats

Creatures target opponent controls attack this turn if able. During that player's next untap step, creatures they control don't untap.
Cycling {2} ({2}, Discard this card: Draw a card.)

Hunted Phantasm

Hunted Phantasm can't be blocked.
When Hunted Phantasm enters the battlefield, target opponent creates five 1/1 red Goblin creature tokens.

Seed the Land

Whenever a land enters the battlefield, its controller creates a 1/1 green Snake creature token.

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.

Pulse of the Grid

Draw two cards, then discard a card. Then if an opponent has more cards in hand than you, return Pulse of the Grid to its owner's hand.

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Thunderstaff

As long as Thunderstaff is untapped, if a creature would deal combat damage to you, prevent 1 of that damage.
{2}, {T}: Attacking creatures get +1/+0 until end of turn.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Azorius Signet

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Simic Growth Chamber

Simic Growth Chamber enters the battlefield tapped.
When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Selesnya Sanctuary

Selesnya Sanctuary enters the battlefield tapped.
When Selesnya Sanctuary enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Collective Restraint

Domain — Creatures can't attack you unless their controller pays {X} for each creature they control that's attacking you, where X is the number of basic land types among lands you control.

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Deputy of Detention

When Deputy of Detention enters the battlefield, exile target nonland permanent an opponent controls and all other nonland permanents that player controls with the same name as that permanent until Deputy of Detention leaves the battlefield.

Edge of Autumn

If you control four or fewer lands, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Cycling—Sacrifice a land. (Sacrifice a land, Discard this card: Draw a card.)

Questing Phelddagrif

{G}: Questing Phelddagrif gets +1/+1 until end of turn. Target opponent creates a 1/1 green Hippo creature token.
{W}: Questing Phelddagrif gains protection from black and from red until end of turn. Target opponent gains 2 life.
{U}: Questing Phelddagrif gains flying until end of turn. Target opponent may draw a card.

Titania's Song

Each noncreature artifact loses all abilities and becomes an artifact creature with power and toughness each equal to its mana value. If Titania's Song leaves the battlefield, this effect continues until end of turn.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Phelddagrif

{G}: Phelddagrif gains trample until end of turn. Target opponent creates a 1/1 green Hippo creature token.
{W}: Phelddagrif gains flying until end of turn. Target opponent gains 2 life.
{U}: Return Phelddagrif to its owner's hand. Target opponent may draw a card.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Sunpetal Grove

Sunpetal Grove enters the battlefield tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Bountiful Promenade

Bountiful Promenade enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Ghostly Prison

Benefactor's Draught

Untap all creatures. Until end of turn, whenever a creature an opponent controls blocks, draw a card.
Draw a card.