Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.
Whenever you cast a Cat spell, create a 1/1 white Dog creature token.
{R}{G}{W}, {T}: Rin and Seri, Inseparable deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Sacred Armory

{2}: Target creature gets +1/+0 until end of turn.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Forest

Lightning Skelemental

Trample, haste
Whenever Lightning Skelemental deals combat damage to a player, that player discards two cards.
At the beginning of the end step, sacrifice Lightning Skelemental.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Akoum Hellhound

Landfall — Whenever a land you control enters, Akoum Hellhound gets +2/+2 until end of turn.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Ball Lightning.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Blazing Hellhound

{1}, Sacrifice another creature: Blazing Hellhound deals 1 damage to any target.

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.)

Mountain

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.

Searing Blood

Searing Blood deals 2 damage to target creature. When that creature dies this turn, Searing Blood deals 3 damage to the creature's controller.

Temporal Aperture

{5}, {T}: Shuffle your library, then reveal the top card. Until end of turn, for as long as that card remains on top of your library, play with the top card of your library revealed and you may play that card without paying its mana cost. (If it has X in its mana cost, X is 0.)

Zodiac Dog

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Flame Burst

Flame Burst deals X damage to any target, where X is 2 plus the number of cards named Flame Burst in all graveyards.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Flame Jab

Flame Jab deals 1 damage to any target.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Flame Blitz

At the beginning of your end step, Flame Blitz deals 5 damage to each planeswalker.
Cycling {2} ({2}, Discard this card: Draw a card.)

Arcbound Slasher

Modular 4 (This creature enters with four +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Riot (This creature enters with your choice of an additional +1/+1 counter or haste.)

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Lightning Phoenix

Flying, haste
Lightning Phoenix can't block.
At the beginning of your end step, if an opponent was dealt 3 or more damage this turn, you may pay {R}. If you do, return Lightning Phoenix from your graveyard to the battlefield.

Adorned Pouncer

Double strike
Eternalize {3}{W}{W} ({3}{W}{W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Cat with no mana cost. Eternalize only as a sorcery.)

Hellfire Mongrel

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Hellfire Mongrel deals 2 damage to that player.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Searing Blaze

Searing Blaze deals 1 damage to target player or planeswalker and 1 damage to target creature that player or that planeswalker's controller controls.
Landfall — If you had a land enter the battlefield under your control this turn, Searing Blaze deals 3 damage to that player or planeswalker and 3 damage to that creature instead.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Wildfire Cerberus

{5}{R}{R}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
When Wildfire Cerberus becomes monstrous, it deals 2 damage to each opponent and each creature they control.

Arcbound Mouser

Lifelink
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Swamp

Underworld Rage-Hound

Underworld Rage-Hound attacks each combat if able.
Escape—{3}{R}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Underworld Rage-Hound escapes with a +1/+1 counter on it.

Ashmouth Hound

Whenever Ashmouth Hound blocks or becomes blocked by a creature, Ashmouth Hound deals 1 damage to that creature.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Black Market Tycoon

At the beginning of your upkeep, Black Market Tycoon deals 2 damage to you for each Treasure you control.
{T}: Create a Treasure token.

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Fiery Hellhound

{R}: Fiery Hellhound gets +1/+0 until end of turn.

Boros Mastiff

Battalion — Whenever Boros Mastiff and at least two other creatures attack, Boros Mastiff gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Lightning Blast

Lightning Blast deals 4 damage to any target.

Arcbound Shikari

First strike
When Arcbound Shikari enters, put a +1/+1 counter on each other artifact creature you control.
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Plains

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Wild Mongrel

Discard a card: Wild Mongrel gets +1/+1 and becomes the color of your choice until end of turn.

Chandra's Magmutt

{T}: Chandra's Magmutt deals 1 damage to target player or planeswalker.

Wild Dogs

At the beginning of your upkeep, if a player has more life than each other player, the player with the most life gains control of Wild Dogs.
Cycling {2} ({2}, Discard this card: Draw a card.)

Bolt Hound

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Bolt Hound attacks, other creatures you control get +1/+0 until end of turn.