Runaway Boulder

Flash
When Runaway Boulder enters, it deals 6 damage to target creature an opponent controls.
Cycling {2} ({2}, Discard this card: Draw a card.)

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Enlightened Ascetic

When Enlightened Ascetic enters, you may destroy target enchantment.

Argivian Cavalier

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
When Argivian Cavalier enters, create a 1/1 white Soldier creature token.

Blacksmith's Skill

Target permanent gains hexproof and indestructible until end of turn. If it's an artifact creature, it gets +2/+2 until end of turn.

Cathar Commando

Flash (You may cast this spell any time you could cast an instant.)
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Prismatic Strands

Prevent all damage that sources of the color of your choice would deal this turn.
Flashback—Tap an untapped white creature you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Alchemist's Vial

When Alchemist's Vial enters, draw a card.
{1}, {T}, Sacrifice Alchemist's Vial: Target creature can't attack or block this turn.

Glint Hawk

Flying
When Glint Hawk enters, sacrifice it unless you return an artifact you control to its owner's hand.

Loxodon Sergeant

Vigilance
When Loxodon Sergeant enters, other creatures you control gain vigilance until end of turn.

Hopeful Vigil

When Hopeful Vigil enters, create a 2/2 white Knight creature token with vigilance.
When Hopeful Vigil is put into a graveyard from the battlefield, scry 2.
{2}{W}: Sacrifice Hopeful Vigil.

Prized Statue

When Prized Statue enters or is put into a graveyard from the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Aviary Mechanic

When Aviary Mechanic enters, you may return another permanent you control to its owner's hand.

Omen of the Sun

Flash
When Omen of the Sun enters, create two 1/1 white Human Soldier creature tokens and you gain 2 life.
{2}{W}, Sacrifice Omen of the Sun: Scry 2.

Benevolent Bodyguard

Sacrifice Benevolent Bodyguard: Target creature you control gains protection from the color of your choice until end of turn.

Chains of Custody

Enchant creature you control
When Chains of Custody enters, exile target nonland permanent an opponent controls until Chains of Custody leaves the battlefield.
Enchanted creature has ward {2}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Court Street Denizen

Whenever another white creature you control enters, tap target creature an opponent controls.

Ancestral Blade

When Ancestral Blade enters, create a 1/1 white Soldier creature token, then attach Ancestral Blade to it.
Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Fortifying Provisions

Creatures you control get +0/+1.
When Fortifying Provisions enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Flicker of Fate

Exile target creature or enchantment, then return it to the battlefield under its owner's control.

Shelter

Target creature you control gains protection from the color of your choice until end of turn.
Draw a card.

Kor Cartographer

When Kor Cartographer enters, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Tinker's Tote

When Tinker's Tote enters, create two 1/1 colorless Gnome artifact creature tokens.
{W}, Sacrifice Tinker's Tote: You gain 3 life.

Inherited Envelope

When Inherited Envelope enters, the Ring tempts you.
{T}: Add one mana of any color.

Nimblewright Schematic

When Nimblewright Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Construct artifact creature token.

Take Vengeance

Impassioned Orator

Whenever another creature you control enters, you gain 1 life.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Far Traveler

Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."

Minimus Containment

Enchant nonland permanent
Enchanted permanent is a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color," and it loses all other abilities. (If it was a creature, it's no longer a creature.)

Cogworker's Puzzleknot

When Cogworker's Puzzleknot enters, create a 1/1 colorless Servo artifact creature token.
{1}{W}, Sacrifice Cogworker's Puzzleknot: Create a 1/1 colorless Servo artifact creature token.

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Lumithread Field

Creatures you control get +0/+1.
Morph {1}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Gilded Pinions

When Gilded Pinions enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equipped creature has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Abdel Adrian, Gorion's Ward

When Abdel Adrian, Gorion's Ward enters, exile any number of other nonland permanents you control until Abdel Adrian leaves the battlefield. Create a 1/1 white Soldier creature token for each permanent exiled this way.
Choose a Background (You can have a Background as a second commander.)

Apostle's Blessing

({W/P} can be paid with either {W} or 2 life.)
Target artifact or creature you control gains protection from artifacts or from the color of your choice until end of turn.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Battle Screech

Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Soul Warden

Whenever another creature enters, you gain 1 life.

Plains

Village Bell-Ringer

Flash (You may cast this spell any time you could cast an instant.)
When Village Bell-Ringer enters, untap all creatures you control.

Raffine's Informant

When Raffine's Informant enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Arcane Signet

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

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Smite

Skittering Surveyor

When Skittering Surveyor enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Nurturing Presence

Enchant creature
Enchanted creature has "Whenever a creature you control enters, this creature gets +1/+1 until end of turn."
When Nurturing Presence enters, create a 1/1 white Spirit creature token with flying.

Slip On the Ring

Exile target creature you own, then return it to the battlefield under your control. The Ring tempts you.

Veteran Armorsmith

Other Soldier creatures you control get +0/+1.

Prismatic Lens

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

Makindi Patrol

Rally — Whenever Makindi Patrol or another Ally you control enters, creatures you control gain vigilance until end of turn.

Mycosynth Wellspring

When Mycosynth Wellspring enters or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Veteran Swordsmith

Other Soldier creatures you control get +1/+0.

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Lyev Decree

Detain up to two target creatures your opponents control. (Until your next turn, those creatures can't attack or block and their activated abilities can't be activated.)

Warded Battlements

Defender (This creature can't attack.)
Attacking creatures you control get +1/+0.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Spirited Companion

When Spirited Companion enters, draw a card.

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.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)