Endless Scream

Enchant creature
Endless Scream enters with X scream counters on it.
Enchanted creature gets +1/+0 for each scream counter on Endless Scream.

Chainsaw

When Chainsaw enters, it deals 3 damage to up to one target creature.
Whenever one or more creatures die, put a rev counter on Chainsaw.
Equipped creature gets +X/+0, where X is the number of rev counters on Chainsaw.
Equip {3}

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Tarrian's Soulcleaver

Equipped creature has vigilance.
Whenever another artifact or creature is put into a graveyard from the battlefield, put a +1/+1 counter on equipped creature.
Equip {2}

Rabble-Rouser

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
{R}, {T}: Attacking creatures get +X/+0 until end of turn, where X is Rabble-Rouser's power.

Demonmail Hauberk

Equipped creature gets +4/+2.
Equip—Sacrifice a creature.

Blazing Shoal

You may exile a red card with mana value X from your hand rather than pay this spell's mana cost.
Target creature gets +X/+0 until end of turn.

Piston Sledge

When Piston Sledge enters, attach it to target creature you control.
Equipped creature gets +3/+1.
Equip—Sacrifice an artifact.

Thirsting Axe

Equipped creature gets +4/+0.
At the beginning of your end step, if equipped creature didn't deal combat damage to a creature this turn, sacrifice it.
Equip {2}

Stitcher's Graft

Equipped creature gets +3/+3.
Whenever equipped creature attacks, it doesn't untap during its controller's next untap step.
Whenever Stitcher's Graft becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Wick, the Whorled Mind

Whenever Wick or another Rat you control enters, create a 1/1 black Snail creature token if you don't control a Snail. Otherwise, put a +1/+1 counter on a Snail you control.
{U}{B}{R}, Sacrifice a Snail: Wick deals damage equal to the sacrificed creature's power to each opponent. Then draw cards equal to the sacrificed creature's power.

Brambleguard Captain

At the beginning of combat on your turn, target creature you control gets +X/+0 until end of turn, where X is Brambleguard Captain's power.

Infernal Plunge

As an additional cost to cast this spell, sacrifice a creature.
Add {R}{R}{R}.

Unleash Fury

Double the power of target creature until end of turn.

Grafted Wargear

Equipped creature gets +3/+2.
Whenever Grafted Wargear becomes unattached from a permanent, sacrifice that permanent.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Strength-Testing Hammer

Whenever equipped creature attacks, roll a six-sided die. That creature gets +X/+0 until end of turn, where X is the result. Then if it has the greatest power or is tied for greatest power among creatures on the battlefield, draw a card.
Equip {3}

Wine of Blood and Iron

{4}: Target creature gets +X/+0 until end of turn, where X is its power. Sacrifice Wine of Blood and Iron at the beginning of the next end step.

Drach'Nyen

Echo of the First Murder — When Drach'Nyen enters, exile up to one target creature.
Daemon Sword — Equipped creature has menace and gets +X/+0, where X is the exiled card's power.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Runechanter's Pike

Equipped creature has first strike and gets +X/+0, where X is the number of instant and sorcery cards in your graveyard.
Equip {2}

Demonspine Whip

{X}: Equipped creature gets +X/+0 until end of turn.
Equip {1}

Sol Ring

Mana Geyser

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

Fatal Frenzy

Until end of turn, target creature you control gains trample and gets +X/+0, where X is its power. Sacrifice it at the beginning of the next end step.

Sweeping Cleave

Target creature you control gains double strike until end of turn. (Then exile this card. You may cast the artifact later from exile.)

Two-Handed Axe

Whenever equipped creature attacks, double its power until end of turn.
Equip {1}{R}

Two-Handed Axe // Sweeping Cleave

Battle Hymn

Junk Jet

When Junk Jet enters, create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")
{3}, Sacrifice another artifact: Double equipped creature's power until end of turn.
Equip {1}