Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Basalt Ravager

When this creature enters, it deals X damage to any target, where X is the greatest number of creatures you control that have a creature type in common.

Borderland Behemoth

Trample
This creature gets +4/+4 for each other Giant you control.

Passionate Archaeologist

Commander creatures you own have "Whenever you cast a spell from exile, this creature deals damage equal to that spell's mana value to target opponent."

Random Encounter

Shuffle your library, then mill four cards. Put each creature card milled this way onto the battlefield. They gain haste. At the beginning of the next end step, return those creatures to their owner's hand.
Flashback {6}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Flameshadow Conjuring

Whenever a nontoken creature you control enters, you may pay {R}. If you do, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Stinkdrinker Daredevil

Giant spells you cast cost {2} less to cast.

Seething Song

Enraged Giant

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Trample, haste

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

The Eternity Elevator

{T}: Add {C}{C}{C}.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery.)
STATION 20+
{T}: Add X mana of any one color, where X is the number of charge counters on The Eternity Elevator.

Giant Harbinger

When this creature enters, you may search your library for a Giant card, reveal it, then shuffle and put that card on top.

Stone Giant

{T}: Target creature you control with toughness less than this creature's power gains flying until end of turn. Destroy that creature at the beginning of the next end step.

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Crush Underfoot

Choose a Giant creature you control. It deals damage equal to its power to target creature.

Tectonic Giant

Whenever this creature attacks or becomes the target of a spell an opponent controls, choose one —
• This creature deals 3 damage to each opponent.
• Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

Molten Echoes

As this enchantment enters, choose a creature type.
Whenever a nontoken creature you control of the chosen type enters, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Arcane Signet

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

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)

Calamity Bearer

If a Giant source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Fire Giant's Fury

Target Giant you control gets +2/+2 and gains trample until end of turn. Whenever it deals combat damage to a player this turn, exile that many cards from the top of your library. Until the end of your next turn, you may play those cards.

Industrial Advancement

At the beginning of your end step, you may sacrifice a creature. If you do, look at the top X cards of your library, where X is that creature's mana value. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Impelled Giant

Trample
Tap an untapped red creature you control other than this creature: This creature gets +X/+0 until end of turn, where X is the power of the creature tapped this way.

Thundercloud Shaman

When this creature enters, it deals damage equal to the number of Giants you control to each non-Giant creature.

Endless Sands

{T}: Add {C}.
{2}, {T}: Exile target creature you control.
{4}, {T}, Sacrifice this land: Return each creature card exiled with this land to the battlefield under its owner's control.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Surtland Flinger

Whenever this creature attacks, you may sacrifice another creature. When you do, this creature deals damage equal to the sacrificed creature's power to any target. If the sacrificed creature was a Giant, this creature deals twice that much damage instead.

Quakebringer

Your opponents can't gain life.
At the beginning of your upkeep, Quakebringer deals 2 damage to each opponent. This ability triggers only if Quakebringer is on the battlefield or if Quakebringer is in your graveyard and you control a Giant.
Foretell {2}{R}{R}

Pain for All

Enchant creature you control
When this Aura enters, enchanted creature deals damage equal to its power to any other target.
Whenever enchanted creature is dealt damage, it deals that much damage to each opponent.

Ilharg, the Raze-Boar

Trample
Whenever Ilharg attacks, you may put a creature card from your hand onto the battlefield tapped and attacking. Return that creature to your hand at the beginning of the next end step.
When Ilharg dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Hamletback Goliath

Whenever another creature enters, you may put X +1/+1 counters on this creature, where X is that creature's power.

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

Sol Ring

Tannuk, Steadfast Second

Other creatures you control have haste.
Artifact cards and red creature cards in your hand have warp {2}{R}. (You may cast a card from your hand for its warp cost. Exile that permanent at the beginning of the next end step, then you may cast it from exile on a later turn.)

Mana Geyser

Add {R} for each tapped land your opponents control.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Cragganwick Cremator

When this creature enters, discard a card at random. If you discard a creature card this way, this creature deals damage equal to that card's power to target player or planeswalker.

Surtr, Fiery Jötun

Trample (This creature can deal excess combat damage to the player it's attacking.)
Whenever you cast a historic spell, Surtr deals 3 damage to any target. (Artifacts, legendaries, and Sagas are historic.)

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

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. This artifact deals damage to the player equal to the number of creatures tapped this way.

Furystoke Giant

When this creature enters, other creatures you control gain "{T}: This creature deals 2 damage to any target" until end of turn.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Bearer of the Heavens

When this creature dies, destroy all permanents at the beginning of the next end step.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Hill Gigas

Trample, haste
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Bloodfire Colossus

{R}, Sacrifice this creature: It deals 6 damage to each creature and each player.

Callous Giant

If a source would deal 3 or less damage to this creature, prevent that damage.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Sunrise Sovereign

Other Giant creatures you control get +2/+2 and have trample.

Firbolg Flutist

Enthralling Performance — When this creature enters, gain control of target creature you don't control until end of turn. Untap it. It gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Ingenuity Engine

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
{1}, {T}, Sacrifice an artifact: Return target artifact you control to its owner's hand.

Mirror of Life Trapping

Whenever a creature enters, if it was cast, exile it, then return all other permanent cards exiled with this artifact to the battlefield under their owners' control.

Squash

This spell costs {3} less to cast if you control a Giant.
Squash deals 6 damage to target creature or planeswalker.

Portal to Phyrexia

When this artifact enters, each opponent sacrifices three creatures of their choice.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control. It's a Phyrexian in addition to its other types.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Mountain

Warped Space

Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast from exile.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer

At the beginning of your upkeep, exile the top card of your library. You may play it this turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer // Warped Space

Devastating Onslaught

Create X tokens that are copies of target artifact or creature you control. Those tokens gain haste until end of turn. Sacrifice them at the beginning of the next end step.

Warchief Giant

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Into the Time Vortex

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
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.)

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Worldgorger Dragon

Flying, trample
When this creature enters, exile all other permanents you control.
When this creature leaves the battlefield, return the exiled cards to the battlefield under their owners' control.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.