Mountain

Sokenzan Bruiser

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

Call for Blood

As an additional cost to cast this spell, sacrifice a creature.
Target creature gets -X/-X until end of turn, where X is the sacrificed creature's power.

Blood Speaker

At the beginning of your upkeep, you may sacrifice this creature. If you do, search your library for a Demon card, reveal that card, put it into your hand, then shuffle.
Whenever a Demon you control enters, return this card from your graveyard to your hand.

Painwracker Oni

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, sacrifice a creature if you don't control an Ogre.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Oni Possession

Enchant creature
At the beginning of your upkeep, sacrifice a creature.
Enchanted creature gets +3/+3 and has trample.
Enchanted creature is a Demon Spirit.

Mark of the Oni

Enchant creature
You control enchanted creature.
At the beginning of the end step, if you control no Demons, sacrifice this Aura.

Scourge of Numai

At the beginning of your upkeep, you lose 2 life if you don't control an Ogre.

Kumano's Blessing

Flash
Enchant creature
If a creature dealt damage by enchanted creature this turn would die, exile it instead.

Bloodthirsty Ogre

{T}: Put a devotion counter on this creature.
{T}: Target creature gets -X/-X until end of turn, where X is the number of devotion counters on this creature. Activate only if you control a Demon.

Frost Ogre

Takenuma Bleeder

Whenever this creature attacks or blocks, you lose 1 life if you don't control a Demon.

Yukora, the Prisoner

When Yukora leaves the battlefield, sacrifice all non-Ogre creatures you control.

Swallowing Plague

Swallowing Plague deals X damage to target creature and you gain X life.

Shinka Gatekeeper

Whenever this creature is dealt damage, it deals that much damage to you.

Deathcurse Ogre

When this creature dies, each player loses 3 life.

Torrent of Stone

Torrent of Stone deals 4 damage to target creature.
Splice onto Arcane—Sacrifice two Mountains. (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Villainous Ogre

This creature can't block.
As long as you control a Demon, this creature has "{B}: Regenerate this creature."

Hearth Kami

{X}, Sacrifice this creature: Destroy target artifact with mana value X.

Bile Urchin

Sacrifice this creature: Target player loses 1 life.

Goka the Unjust

{T}: Goka deals 4 damage to target creature that was dealt damage this turn.

Initiate of Blood

{T}: This creature deals 1 damage to target creature that was dealt damage this turn. When that creature dies this turn, flip this creature.

Initiate of Blood // Goka the Unjust

Swamp

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)