Horobi's Whisper

If you control a Swamp, destroy target nonblack creature.
Splice onto Arcane—Exile four cards from your graveyard. (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.)

Swamp

Rollick of Abandon

All creatures get +2/-2 until end of turn.

Gnarled Scarhide

Bestow {3}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Gnarled Scarhide can't block.
Enchanted creature gets +2/+1 and can't block.

Starfall

Starfall deals 3 damage to target creature. If that creature is an enchantment, Starfall deals 3 damage to that creature's controller.

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.

Ragemonger

Minotaur spells you cast cost {B}{R} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a Minotaur spell with mana cost {2}{R}, it costs {2} to cast.)

Rouse the Mob

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Any number of target creatures each get +2/+0 and gain trample until end of turn.

Weight of the Underworld

Enchant creature
Enchanted creature gets -3/-2.

Kragma Warcaller

Minotaur creatures you control have haste.
Whenever a Minotaur you control attacks, it gets +2/+0 until end of turn.

Magma Spray

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Fanatic of Mogis

When Fanatic of Mogis enters, it deals damage to each opponent equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

Spiteful Blow

Mountain

Minotaur Skullcleaver

Haste
When Minotaur Skullcleaver enters, it gets +2/+0 until end of turn.

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.)