Mishra, Claimed by Gix

Whenever you attack, each opponent loses X life and you gain X life, where X is the number of attacking creatures. If Mishra, Claimed by Gix and a creature named Phyrexian Dragon Engine are attacking, and you both own and control them, exile them, then meld them into Mishra, Lost to Phyrexia. It enters the battlefield tapped and attacking.

Flamewar, Streetwise Operative

Living metal (As long as it's your turn, this Vehicle is also a creature.)
Menace, deathtouch
Whenever Flamewar deals combat damage to a player, exile that many cards from the top of your library face down. Put an intel counter on each of them. Convert Flamewar.

Flamewar, Brash Veteran

More Than Meets the Eye {B}{R} (You may cast this card converted for {B}{R}.)
Sacrifice another artifact: Put a +1/+1 counter on Flamewar and convert it. Activate only as a sorcery.
{1}, Discard your hand: Put all exiled cards you own with intel counters on them into your hand.

Flamewar, Brash Veteran // Flamewar, Streetwise Operative

Daretti, Ingenious Iconoclast

+1: Create a 1/1 colorless Construct artifact creature token with defender.
−1: You may sacrifice an artifact. If you do, destroy target artifact or creature.
−6: Choose target artifact card in a graveyard or artifact on the battlefield. Create three tokens that are copies of it.

Rakdos Charm

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

Phyrexian Dragon Engine

Double strike
When Phyrexian Dragon Engine enters the battlefield from your graveyard, you may discard your hand. If you do, draw three cards.
Unearth {3}{R}{R}
(Melds with Mishra, Claimed by Gix.)

Bedevil

Destroy target artifact, creature, or planeswalker.

Oni-Cult Anvil

Whenever one or more artifacts you control leave the battlefield during your turn, create a 1/1 colorless Construct artifact creature token. This ability triggers only once each turn.
{T}, Sacrifice an artifact: Oni-Cult Anvil deals 1 damage to each opponent. You gain 1 life.

Mishra, Tamer of Mak Fawa

Permanents you control have "Ward—Sacrifice a permanent."
Each artifact card in your graveyard has unearth {1}{B}{R}. ({1}{B}{R}: Return the card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)