Swamp

Grinding Station

{T}, Sacrifice an artifact: Target player mills three cards.
Whenever an artifact enters, you may untap Grinding Station.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Underground Sea

Dark Ritual

Throne of Geth

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Go for the Throat

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Myr Retriever

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

Tundra

Shred Memory

Exile up to four target cards from a single graveyard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Hymn to Tourach

Target player discards two cards at random.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Heartless Summoning

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