Have

Everlasting Torment

Players can't gain life.
Damage can't be prevented.
All damage is dealt as though its source had wither. (A source with wither deals damage to creatures in the form of -1/-1 counters.)

Kulrath Knight

Flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Creatures your opponents control with counters on them can't attack or block.

Swamp

Mountain

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Akoum Refuge

Akoum Refuge enters the battlefield tapped.
When Akoum Refuge enters the battlefield, you gain 1 life.
{T}: Add {B} or {R}.

Sickle Ripper

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Flamekin Harbinger

When Flamekin Harbinger enters the battlefield, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.

Primal Beyond

As Primal Beyond enters the battlefield, you may reveal an Elemental card from your hand. If you don't, Primal Beyond enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Elemental spell or activate an ability of an Elemental.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Stigma Lasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever Stigma Lasher deals damage to a player, that player can't gain life for the rest of the game.

Fists of the Demigod

Enchant creature
As long as enchanted creature is black, it gets +1/+1 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
As long as enchanted creature is red, it gets +1/+1 and has first strike.

Crumbling Ashes

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Blowfly Infestation

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Terminate

Destroy target creature. It can't be regenerated.

Ashenmoor Liege

Other black creatures you control get +1/+1.
Other red creatures you control get +1/+1.
Whenever Ashenmoor Liege becomes the target of a spell or ability an opponent controls, that player loses 4 life.

Nova Chaser

Trample
Champion an Elemental (When this enters the battlefield, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Smokebraider

{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elementals.