Ignition Team

Ignition Team enters the battlefield with X +1/+1 counters on it, where X is the number of tapped lands on the battlefield.
{2}{R}, Remove a +1/+1 counter from Ignition Team: Target land becomes a 4/4 red Elemental creature until end of turn. It's still a land.

Skitter of Lizards

Multikicker {1}{R} (You may pay an additional {1}{R} any number of times as you cast this spell.)
Haste
Skitter of Lizards enters the battlefield with a +1/+1 counter on it for each time it was kicked.

Grudge Keeper

Whenever players finish voting, each opponent who voted for a choice you didn't vote for loses 2 life.

Wrap in Flames

Wrap in Flames deals 1 damage to each of up to three target creatures. Those creatures can't block this turn.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Power of Fire

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to any target."

Mana Geyser

Add {R} for each tapped land your opponents control.

Pitchburn Devils

When Pitchburn Devils dies, it deals 3 damage to any target.

Iterative Analysis

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.)
Whenever you cast an instant or sorcery spell with the chosen name, you may draw a card.

Enraged Revolutionary

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Volcanic Fallout

This spell can't be countered.
Volcanic Fallout deals 2 damage to each creature and each player.

Morkrut Banshee

Morbid — When Morkrut Banshee enters the battlefield, if a creature died this turn, target creature gets -4/-4 until end of turn.

Impulsive Pilferer

When Impulsive Pilferer dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Cinder Wall

Defender
When Cinder Wall blocks, destroy it at end of combat.

Brimstone Volley

Brimstone Volley deals 3 damage to any target.
Morbid — Brimstone Volley deals 5 damage instead if a creature died this turn.

Necromantic Thirst

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may return target creature card from your graveyard to your hand.

Grenzo's Cutthroat

First strike
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Boldwyr Intimidator

Cowards can't block Warriors.
{R}: Target creature becomes a Coward until end of turn.
{2}{R}: Target creature becomes a Warrior until end of turn.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature, then sacrifices a land.

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Deathforge Shaman

Multikicker {R} (You may pay an additional {R} any number of times as you cast this spell.)
When Deathforge Shaman enters the battlefield, it deals damage to target player or planeswalker equal to twice the number of times it was kicked.