Underhanded Designs

Whenever an artifact you control enters, you may pay {1}. If you do, each opponent loses 1 life and you gain 1 life.
{1}{B}, Sacrifice Underhanded Designs: Destroy target creature. Activate only if you control two or more artifacts.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

The Elderspell

Destroy any number of target planeswalkers. Choose a planeswalker you control. Put two loyalty counters on it for each planeswalker destroyed this way.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Duplicant

Imprint — When Duplicant enters, you may exile target nontoken creature.
As long as a card exiled with Duplicant is a creature card, Duplicant has the power, toughness, and creature types of the last creature card exiled with Duplicant. It's still a Shapeshifter.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Sign in Blood

Target player draws two cards and loses 2 life.

Lost Legacy

Choose a nonartifact, nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Filigree Familiar

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

Noxious Gearhulk

Menace
When Noxious Gearhulk enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Swamp

Traveler's Amulet

{1}, Sacrifice Traveler's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Rustspore Ram

When Rustspore Ram enters, destroy target Equipment.

Lodestone Myr

Trample
Tap an untapped artifact you control: Lodestone Myr gets +1/+1 until end of turn.