Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Demonic Vigor

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return that card to its owner's hand.

Take Vengeance

Descend upon the Sinful

Exile all creatures.
Delirium — Create a 4/4 white Angel creature token with flying if there are four or more card types among cards in your graveyard.

Stockpiling Celebrant

When Stockpiling Celebrant enters the battlefield, you may return another target nonland permanent you control to its owner's hand. If you do, scry 2.

Vodalian Wave-Knight

Whenever you draw a card, put a +1/+1 counter on each other Merfolk and/or Knight you control.

Invoke the Divine

Destroy target artifact or enchantment. You gain 4 life.

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle Decree of Pain, all creatures get -2/-2 until end of turn.

Knight of New Benalia

Sol Ring

Tenacious Tomeseeker

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
When Tenacious Tomeseeker enters the battlefield, if it was bargained, return target instant or sorcery card from your graveyard to your hand.

Revitalize

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Lost Legion

When Lost Legion enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

Rider in Need

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the creature later from exile.)

Lonesome Unicorn

Lonesome Unicorn // Rider in Need

Revoke Existence

Crawlspace

No more than two creatures can attack you each combat.

Knight of Malice

First strike
Hexproof from white (This creature can't be the target of white spells or abilities your opponents control.)
Knight of Malice gets +1/+0 as long as any player controls a white permanent.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Cabal Paladin

Whenever you cast a historic spell, Cabal Paladin deals 2 damage to each opponent. (Artifacts, legendaries, and Sagas are historic.)

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Duskmantle Seer

Flying
At the beginning of your upkeep, each player reveals the top card of their library, loses life equal to that card's mana value, then puts it into their hand.

Eviscerate

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Sidar Jabari of Zhalfir

Eminence — Whenever you attack with one or more Knights, if Sidar Jabari of Zhalfir is in the command zone or on the battlefield, draw a card, then discard a card.
Flying, first strike
Whenever Sidar Jabari deals combat damage to a player, return target Knight creature card from your graveyard to the battlefield.

Call the Cavalry

Create two 2/2 white Knight creature tokens with vigilance.

Deathless Ancient

Flying
Tap three untapped Vampires you control: Return Deathless Ancient from your graveyard to your hand.

Command Tower

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

Divination

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Plains

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters the battlefield tapped.

Weathered Runestone

Nonland permanent cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Evolving Wilds

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

Betroth the Beast

Create a Royal Role token attached to target creature you control. (Enchanted creature gets +1/+1 and has ward {1}.)

Besotted Knight

Besotted Knight // Betroth the Beast

March of the Drowned

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target Pirate cards from your graveyard to your hand.

Blessed Light

Clarion Cathars

When Clarion Cathars enters the battlefield, create a 1/1 white Human creature token.

Harsh Sustenance

Harsh Sustenance deals X damage to any target and you gain X life, where X is the number of creatures you control.

Benalish Marshal

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters the battlefield, choose a creature type.
Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

Soul Salvage

Return up to two target creature cards from your graveyard to your hand.

Justiciar's Portal

Exile target creature you control, then return that card to the battlefield under its owner's control. It gains first strike until end of turn.

Gryffwing Cavalry

Flying
Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
Whenever Gryffwing Cavalry attacks, you may pay {1}{W}. If you do, target attacking creature without flying gains flying until end of turn.

Gryff Rider

Flying
Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)

Child of Night

Island

Locthwain Paladin

Menace (This creature can't be blocked except by two or more creatures.)
Adamant — If at least three black mana was spent to cast this spell, Locthwain Paladin enters the battlefield with a +1/+1 counter on it.

Knights' Charge

Whenever a Knight you control attacks, each opponent loses 1 life and you gain 1 life.
{6}{W}{B}, Sacrifice Knights' Charge: Return all Knight creature cards from your graveyard to the battlefield.

Viconia, Drow Apostate

At the beginning of your upkeep, if there are four or more creature cards in your graveyard, return a creature card at random from your graveyard to your hand.
Choose a Background (You can have a Background as a second commander.)

Transguild Promenade

Transguild Promenade enters the battlefield tapped.
When Transguild Promenade enters the battlefield, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Knight Exemplar

First strike (This creature deals combat damage before creatures without first strike.)
Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Gallant Pie-Wielder

First strike
Celebration — Gallant Pie-Wielder has double strike as long as two or more nonland permanents entered the battlefield under your control this turn.

Enchant creature
Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)

Windbrisk Heights

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Windbrisk Heights enters the battlefield tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Curry Favor

You gain X life and each opponent loses X life, where X is the number of Knights you control.

Smitten Swordmaster

Smitten Swordmaster // Curry Favor

Healing Grace

Prevent the next 3 damage that would be dealt to any target this turn by a source of your choice. You gain 3 life.

Promising Vein

{T}: Add {C}.
{1}, {T}, Sacrifice Promising Vein: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Impale

Unknown Shores

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Citadel Siege

As Citadel Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of combat on your turn, put two +1/+1 counters on target creature you control.
• Dragons — At the beginning of combat on each opponent's turn, tap target creature that player controls.

Mesa Cavalier

Flying
When Mesa Cavalier enters the battlefield, you gain 2 life.

Vito's Inquisitor

{B}, Sacrifice another creature or artifact: Put a +1/+1 counter on Vito's Inquisitor. It gains menace until end of turn.

Shire Terrace

{T}: Add {C}.
{1}, {T}, Sacrifice Shire Terrace: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.