Riot Spikes

({B/R} can be paid with either {B} or {R}.)
Enchant creature
Enchanted creature gets +2/-1.

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.)

Ruin Processor

When you cast this spell, you may put a card an opponent owns from exile into that player's graveyard. If you do, you gain 5 life.

Ring of Xathrid

{2}: Regenerate equipped creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's black.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Manalith

Phthisis

Destroy target creature. Its controller loses life equal to its power plus its toughness.
Suspend 5—{1}{B} (Rather than cast this card from your hand, you may pay {1}{B} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis, the Hate-Twisted deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Go Blank

Target player discards two cards. Then exile that player's graveyard.

Cateran Enforcer

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{4}, {T}: Search your library for a Mercenary permanent card with mana value 4 or less, put it onto the battlefield, then shuffle.

Moaning Wall

Defender
Cycling {2} ({2}, Discard this card: Draw a card.)

Scrounger of Souls

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Polluted Mire

Polluted Mire enters tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sifter of Skulls

Devoid (This card has no color.)
Whenever another nontoken creature you control dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}." ({C} represents colorless mana.)

Swamp

Casting of Bones

Enchant creature
When enchanted creature dies, draw three cards, then discard one of them.

Touch of Moonglove

Target creature you control gets +1/+0 and gains deathtouch until end of turn. Whenever a creature dealt damage by that creature dies this turn, its controller loses 2 life. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Vial of Poison

{1}, Sacrifice Vial of Poison: Target creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Subcontract

A person outside the game looks at target opponent's hand and chooses a nonland card from it. That player discards that card.

Guardians of Meletis

Skyclave Shadowcat

{1}{B}, Sacrifice another creature: Put a +1/+1 counter on Skyclave Shadowcat.
Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

Unnerve

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Footbottom Feast

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.