Urborg Mindsucker

{B}, Sacrifice Urborg Mindsucker: Target opponent discards a card at random. Activate only as a sorcery.

Aetherplasm

Whenever Aetherplasm blocks a creature, you may return Aetherplasm to its owner's hand. If you do, you may put a creature card from your hand onto the battlefield blocking that creature.

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Extract Brain

Target opponent chooses X cards from their hand. Look at those cards. You may cast a spell from among them without paying its mana cost.

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Rotlung Reanimator

Whenever Rotlung Reanimator or another Cleric dies, create a 2/2 black Zombie creature token.

Mage-Ring Network

{T}: Add {C}.
{1}, {T}: Put a storage counter on Mage-Ring Network.
{T}, Remove any number of storage counters from Mage-Ring Network: Add {C} for each storage counter removed this way.

Giant Octopus

Shade's Form

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."
When enchanted creature dies, return that card to the battlefield under your control.

Sharding Sphinx

Flying
Whenever an artifact creature you control deals combat damage to a player, you may create a 1/1 blue Thopter artifact creature token with flying.

Peregrine Mask

Equipped creature has defender, flying, and first strike.
Equip {2}

Promising Duskmage

When Promising Duskmage dies, if it had a +1/+1 counter on it, draw a card.

Force Away

Return target creature to its owner's hand.
Ferocious — If you control a creature with power 4 or greater, you may draw a card. If you do, discard a card.

Battlefield Percher

Flying
Battlefield Percher can block only creatures with flying.
{1}{B}: Battlefield Percher gets +1/+1 until end of turn.

Honden of Night's Reach

At the beginning of your upkeep, target opponent discards a card for each Shrine you control.

Glint

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Jace, Wielder of Mysteries

If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player mills two cards. Draw a card.
−8: Draw seven cards. Then if your library has no cards in it, you win the game.

Medomai's Prophecy

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Scry 2.
II — Choose a card name.
III — When you cast a spell with the chosen name for the first time this turn, draw two cards.
IV — Look at the top card of each player's library.

Claws of Gix

{1}, Sacrifice a permanent: You gain 1 life.

Telim'Tor's Darts

{2}, {T}: Telim'Tor's Darts deals 1 damage to target player or planeswalker.

Gift of Tusks

Until end of turn, target creature loses all abilities and becomes a green Elephant with base power and toughness 3/3.

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Cavalier of Night

Lifelink
When Cavalier of Night enters, you may sacrifice another creature. When you do, destroy target creature an opponent controls.
When Cavalier of Night dies, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Frostwalk Bastion

{T}: Add {C}.
{1}{S}: Until end of turn, Frostwalk Bastion becomes a 2/3 Construct artifact creature. It's still a land. ({S} can be paid with one mana from a snow source.)
Whenever Frostwalk Bastion deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Bellowing Crier

When Bellowing Crier enters, draw a card, then discard a card.

Evermind

(Nonexistent mana costs can't be paid.)
Draw a card.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Stir the Sands

Create three 2/2 black Zombie creature tokens.
Cycling {3}{B} ({3}{B}, Discard this card: Draw a card.)
When you cycle Stir the Sands, create a 2/2 black Zombie creature token.

Necropede

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Necropede dies, you may put a -1/-1 counter on target creature.

Infernal Pet

Whenever you cast your second spell each turn, put a +1/+1 counter on Infernal Pet and it gains flying until end of turn.

Spiteful Blow

Rocky Tar Pit

Rocky Tar Pit enters tapped.
{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Scorched Ruins

If Scorched Ruins would enter, sacrifice two untapped lands instead. If you do, put Scorched Ruins onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {C}{C}{C}{C}.

Corpse Cur

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Corpse Cur enters, you may return target creature card with infect from your graveyard to your hand.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Crumbling Vestige

Crumbling Vestige enters tapped.
When Crumbling Vestige enters, add one mana of any color.
{T}: Add {C}. ({C} represents colorless mana.)

Chardalyn Dragon

Feebleness

Flash
Enchant creature
Enchanted creature gets -2/-1.

Foul Play

Destroy target creature with power 2 or less. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Corrupted Crossroads

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a spell with devoid.

Maze's End

This land enters tapped.
{T}: Add {C}.
{3}, {T}, Return this land to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Griffin Canyon

{T}: Add {C}.
{T}: Untap target Griffin. If it's a creature, it gets +1/+1 until end of turn.

Island

Lembas

When Lembas enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Esior, Wardwing Familiar

Flying
Spells your opponents cast that target one or more commanders you control cost {3} more to cast.
Partner (You can have two commanders if both have partner.)

Phyrexian Juggernaut

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Phyrexian Juggernaut attacks each combat if able.

Uyo, Silent Prophet

Flying
{2}, Return two lands you control to their owner's hand: Copy target instant or sorcery spell. You may choose new targets for the copy.

Legion's End

Exile target creature an opponent controls with mana value 2 or less and all other creatures that player controls with the same name as that creature. Then that player reveals their hand and exiles all cards with that name from their hand and graveyard.

Drannith Ruins

{T}: Add {C}.
{2}, {T}: Put two +1/+1 counters on target non-Human creature that entered this turn.

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Augur of Bolas

When Augur of Bolas enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Stallion of Ashmouth

Delirium — {1}{B}: Stallion of Ashmouth gets +1/+1 until end of turn. Activate only if there are four or more card types among cards in your graveyard.

Oath of Scholars

At the beginning of each player's upkeep, that player chooses target player who has more cards in hand than they do and is their opponent. The first player may discard their hand and draw three cards.

Vicious Conquistador

Whenever Vicious Conquistador attacks, each opponent loses 1 life.

Ogre Jailbreaker

Defender
Ogre Jailbreaker can attack as though it didn't have defender as long as you control a Gate.

Rishadan Port

Magosi, the Waterveil

Magosi, the Waterveil enters tapped.
{T}: Add {U}.
{U}, {T}: Put an eon counter on Magosi, the Waterveil. Skip your next turn.
{T}, Remove an eon counter from Magosi, the Waterveil and return it to its owner's hand: Take an extra turn after this one.

Sutured Ghoul

Trample
As Sutured Ghoul enters, exile any number of creature cards from your graveyard.
Sutured Ghoul's power is equal to the total power of the exiled cards and its toughness is equal to their total toughness.

Vedalken Ghoul

Whenever Vedalken Ghoul becomes blocked, defending player loses 4 life.

Stolen Grain

Stolen Grain deals 5 damage to target opponent or planeswalker. You gain 5 life.

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Barrow Ghoul

At the beginning of your upkeep, sacrifice Barrow Ghoul unless you exile the top creature card of your graveyard.

Molting Harpy

Flying
At the beginning of your upkeep, sacrifice Molting Harpy unless you pay {2}.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Spike Cannibal

Spike Cannibal enters with a +1/+1 counter on it.
When Spike Cannibal enters, move all +1/+1 counters from all creatures onto it.

Treachery

Enchant creature
When Treachery enters, untap up to five lands.
You control enchanted creature.

Clay Statue

Black Dragon Gate

Black Dragon Gate enters tapped.
As Black Dragon Gate enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Merfolk Skyscout

Flying
Whenever Merfolk Skyscout attacks or blocks, untap target permanent.

Flayed One

Lifelink
Flesh Flayer — When Flayed One enters, mill three cards.

Moon Heron

Memorial to Genius

Memorial to Genius enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Time Reaper

Flying, haste
Consume Anomaly — Whenever Time Reaper deals combat damage to a player, put target face-up card they own in exile on the bottom of their library. If you do, you gain 3 life.

Swamp

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)