Legendary creatures don't untap during their controllers' untap steps.
When Arena of the Ancients enters the battlefield, tap all legendary creatures.
{2}{R}{R}
Beetleback Chief
Creature - Goblin Warrior
When Beetleback Chief enters the battlefield, create two 1/1 red Goblin creature tokens.
2 /
2
{1}{R}
Bloodmark Mentor
Creature - Goblin Warrior
Red creatures you control have first strike.
1 /
1
{3}
Burnished Hart
Artifact Creature - Elk
{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
2 /
2
--
Castle Embereth
Land
Castle Embereth enters the battlefield tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.
{1}{R}
Cavalcade of Calamity
Enchantment
Whenever a creature you control with power 1 or less attacks, Cavalcade of Calamity deals 1 damage to the player or planeswalker that creature is attacking.
{1}{R}
Circle of Flame
Enchantment
Whenever a creature without flying attacks you or a planeswalker you control, Circle of Flame deals 1 damage to that creature.
{2}{R}{R}
Close Quarters
Enchantment
Whenever a creature you control becomes blocked, Close Quarters deals 1 damage to any target.
{2}
Culling Dais
Artifact
{T}, Sacrifice a creature: Put a charge counter on Culling Dais.
{1}, Sacrifice Culling Dais: Draw a card for each charge counter on Culling Dais.
{1}{R}
Dragon Fodder
Sorcery
Create two 1/1 red Goblin creature tokens.
{3}
Druidic Satchel
Artifact
{2}, {T}: Reveal the top card of your library. If it's a creature card, create a 1/1 green Saproling creature token. If it's a land card, put that card onto the battlefield under your control. If it's a noncreature, nonland card, you gain 2 life.
--
Dwarven Mine
Land - Mountain
({T}: Add {R}.)
Dwarven Mine enters the battlefield tapped unless you control three or more other Mountains.
When Dwarven Mine enters the battlefield untapped, create a 1/1 red Dwarf creature token.
{2}{R}
Electropotence
Enchantment
Whenever a creature enters the battlefield under your control, you may pay {2}{R}. If you do, that creature deals damage equal to its power to any target.
{3}{R}
Empty the Warrens
Sorcery
Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)
{1}{R}{R}
Feldon of the Third Path
Legendary Creature - Human Artificer
{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.
2 /
3
{2}{R}
Ferocity of the Wilds
Enchantment
Attacking non-Human creatures you control get +1/+0 and have trample.
{R}
Foundry Street Denizen
Creature - Goblin Warrior
Whenever another red creature enters the battlefield under your control, Foundry Street Denizen gets +1/+0 until end of turn.
1 /
1
{2}
Genesis Chamber
Artifact
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.
{3}{R}{R}
Goblin Assassin
Creature - Goblin Assassin
Whenever Goblin Assassin or another Goblin enters the battlefield, each player flips a coin. Each player whose coin comes up tails sacrifices a creature.
2 /
2
{1}{R}
Goblin Instigator
Creature - Goblin Rogue
When Goblin Instigator enters the battlefield, create a 1/1 red Goblin creature token.
1 /
1
{X}{1}{R}{R}
Goblin Offensive
Sorcery
Create X 1/1 red Goblin creature tokens.
{1}{R}
Goblin Oriflamme
Enchantment
Attacking creatures you control get +1/+0.
{3}{R}{R}
Goblin Rally
Sorcery
Create four 1/1 red Goblin creature tokens.
{2}{R}
Goblinslide
Enchantment
Whenever you cast a noncreature spell, you may pay {1}. If you do, create a 1/1 red Goblin creature token with haste.
{1}{R}
Harsh Mentor
Creature - Human Cleric
Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.
2 /
2
{1}{R}
Heat of Battle
Enchantment
Whenever a creature blocks, Heat of Battle deals 1 damage to that creature's controller.
{5}{R}
Hellion Eruption
Sorcery
Sacrifice all creatures you control, then create that many 4/4 red Hellion creature tokens.
{2}{R}{R}
Hellrider
Creature - Devil
Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it's attacking.
3 /
3
{3}
Heraldic Banner
Artifact
As Heraldic Banner enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.
{3}
Honor-Worn Shaku
Artifact
{T}: Add {C}.
Tap an untapped legendary permanent you control: Untap Honor-Worn Shaku.
{1}{R}{R}
Hordeling Outburst
Sorcery
Create three 1/1 red Goblin creature tokens.
{1}{R}
Impact Tremors
Enchantment
Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.
{1}
Infiltration Lens
Artifact - Equipment
Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}
{2}
Iron Myr
Artifact Creature - Myr
{T}: Add {R}.
1 /
1
{3}{R}{R}
Kazuul, Tyrant of the Cliffs
Legendary Creature - Ogre Warrior
Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.
5 /
4
--
Kher Keep
Legendary Land
{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.
{2}{R}
Kolaghan Forerunners
Creature - Human Berserker
Trample
Kolaghan Forerunners's power is equal to the number of creatures you control.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)
* /
3
{1}{R}
Krenko's Command
Sorcery
Create two 1/1 red Goblin creature tokens.
{2}{R}
Krenko, Tin Street Kingpin
Legendary Creature - Goblin
Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.
1 /
2
{1}{R}
Loyal Apprentice
Creature - Human Artificer
Haste
Lieutenant -- At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.
2 /
1
{2}{R}
Magus of the Wheel
Creature - Human Wizard
{1}{R}, {T}, Sacrifice Magus of the Wheel: Each player discards their hand, then draws seven cards.
3 /
3
{1}{R}{R}
Massive Raid
Instant
Massive Raid deals damage to any target equal to the number of creatures you control.
{2}
Mind Stone
Artifact
{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.
{5}{R}
Mirror March
Enchantment
Whenever a nontoken creature enters the battlefield under your control, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.
{1}{R}
Mob Justice
Sorcery
Mob Justice deals damage to target player or planeswalker equal to the number of creatures you control.
{1}{R}
Mogg War Marshal
Creature - Goblin Warrior
Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Mogg War Marshal enters the battlefield or dies, create a 1/1 red Goblin creature token.
1 /
1
{1}{R}{R}
Molten Birth
Sorcery
Create two 1/1 red Elemental creature tokens, then flip a coin. If you win the flip, return Molten Birth to its owner's hand.
{4}
Moonsilver Spear
Artifact - Equipment
Equipped creature has first strike.
Whenever equipped creature attacks, create a 4/4 white Angel creature token with flying.
Equip {4}
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
{R}
Norin the Wary
Legendary Creature - Human Warrior
When a player casts a spell or a creature attacks, exile Norin the Wary. Return it to the battlefield under its owner's control at the beginning of the next end step.
2 /
1
{R}
Otherworldly Outburst
Instant
Target creature gets +1/+0 until end of turn. When that creature dies this turn, create a 3/2 colorless Eldrazi Horror creature token.
{3}{R}
Outpost Siege
Enchantment
As Outpost Siege enters the battlefield, choose Khans or Dragons.
• Khans -- At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons -- Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.
{3}{R}
Paragon of Fierce Defiance
Creature - Human Warrior
Other red creatures you control get +1/+1.
{R}, {T}: Another target red creature you control gains haste until end of turn. (It can attack and {T} this turn.)
2 /
2
{2}{R}
Pashalik Mons
Legendary Creature - Goblin Warrior
Whenever Pashalik Mons or another Goblin you control dies, Pashalik Mons deals 1 damage to any target.
{3}{R}, Sacrifice a Goblin: Create two 1/1 red Goblin creature tokens.
2 /
2
{R}
Quest for the Goblin Lord
Enchantment
Whenever a Goblin enters the battlefield under your control, you may put a quest counter on Quest for the Goblin Lord.
As long as Quest for the Goblin Lord has five or more quest counters on it, creatures you control get +2/+0.
{3}{R}{R}
Rite of the Raging Storm
Enchantment
Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this creature."
{3}
Ronin Warclub
Artifact - Equipment
Equipped creature gets +2/+1.
Whenever a creature enters the battlefield under your control, attach Ronin Warclub to that creature.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)
{4}
Soul Foundry
Artifact
Imprint -- When Soul Foundry enters the battlefield, you may exile a creature card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.
{2}
Stormrider Rig
Artifact - Equipment
Equipped creature gets +1/+1.
Whenever a creature enters the battlefield under your control, you may attach Stormrider Rig to it.
Equip {2}
{6}
Thopter Assembly
Artifact Creature - Thopter
Flying
At the beginning of your upkeep, if you control no Thopters other than Thopter Assembly, return Thopter Assembly to its owner's hand and create five 1/1 colorless Thopter artifact creature tokens with flying.
5 /
5
{1}{R}
Tilonalli's Summoner
Creature - Human Shaman
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Whenever Tilonalli's Summoner attacks, you may pay {X}{R}. If you do, create X 1/1 red Elemental creature tokens that are tapped and attacking. At the beginning of the next end step, exile those tokens unless you have the city's blessing.
1 /
1
{2}
Tome of Legends
Artifact
Tome of Legends enters the battlefield with a page counter on it.
Whenever your commander enters the battlefield or attacks, put a page counter on Tome of Legends.
{1}, {T}, Remove a page counter from Tome of Legends: Draw a card.
{1}{R}
Tormenting Voice
Sorcery
As an additional cost to cast this spell, discard a card.
Draw two cards.
{2}{R}
Tuktuk the Explorer
Legendary Creature - Goblin
Haste
When Tuktuk the Explorer dies, create Tuktuk the Returned, a legendary 5/5 colorless Goblin Golem artifact creature token.
1 /
1
{2}
Wall of Junk
Artifact Creature - Wall
Defender (This creature can't attack.)
When Wall of Junk blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)
0 /
7
{5}{R}
Warstorm Surge
Enchantment
Whenever a creature enters the battlefield under your control, it deals damage equal to its power to any target.
{3}{R}
Wildfire Devils
Creature - Devil
When Wildfire Devils enters the battlefield and at the beginning of your upkeep, choose a player at random. That player exiles an instant or sorcery card from their graveyard. Copy that card. You may cast the copy without paying its mana cost.