Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Braid of Fire

Cumulative upkeep—Add {R}. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Rolling Earthquake

Rolling Earthquake deals X damage to each creature without horsemanship and each player.

Hall of Oracles

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When this creature dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

Coalhauler Swine

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

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Mountain

Blazing Sunsteel

Equipped creature gets +1/+0 for each opponent you have.
Whenever equipped creature is dealt damage, it deals that much damage to any target.
Equip {4}

Dockside Extortionist

When this creature enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Mogg Maniac

Whenever this creature is dealt damage, it deals that much damage to target opponent or planeswalker.

Ashling the Pilgrim

{1}{R}: Put a +1/+1 counter on Ashling. If this is the third time this ability has resolved this turn, remove all +1/+1 counters from Ashling, and it deals that much damage to each creature and each player.

Stuffy Doll

Indestructible
As this creature enters, choose a player.
Whenever this creature is dealt damage, it deals that much damage to the chosen player.
{T}: This creature deals 1 damage to itself.

Sol Ring

Brash Taunter

Indestructible
Whenever this creature is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: This creature fights another target creature.

Repercussion

Whenever a creature is dealt damage, this enchantment deals that much damage to that creature's controller.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.