Infernal Tutor

Reveal a card from your hand. Search your library for a card with the same name as that card, reveal it, put it into your hand, then shuffle.
Hellbent — If you have no cards in hand, instead search your library for a card, put it into your hand, then shuffle.

Lashwrithe

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each Swamp you control.
Equip {B/P}{B/P} ({B/P} can be paid with either {B} or 2 life.)

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

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}

Extraplanar Lens

Imprint — When this artifact enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Magus of the Coffers

{2}, {T}: Add {B} for each Swamp you control.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Rhystic Tutor

Unless any player pays {2}, search your library for a card, put that card into your hand, then shuffle.

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Mind Sludge

Target player discards a card for each Swamp you control.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Sima Yi, Wei Field Marshal

Sima Yi's power is equal to the number of Swamps you control.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Maga, Traitor to Mortals

Maga enters with X +1/+1 counters on it.
When Maga enters, target player loses life equal to the number of +1/+1 counters on it.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Cruel Tutor

Walking Atlas

{T}: You may put a land card from your hand onto the battlefield.

Swamp

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Korlash, Heir to Blackblade

Korlash's power and toughness are each equal to the number of Swamps you control.
{1}{B}: Regenerate Korlash.
Grandeur — Discard another card named Korlash, Heir to Blackblade: Search your library for up to two Swamp cards, put them onto the battlefield tapped, then shuffle.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

Demonic Tutor

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Strata Scythe

Imprint — When this Equipment enters, search your library for a land card, exile it, then shuffle.
Equipped creature gets +1/+1 for each land on the battlefield with the same name as the exiled card.
Equip {3}

Glistening Oil

Enchant creature
Enchanted creature has infect.
At the beginning of your upkeep, put a -1/-1 counter on enchanted creature.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Cabal Coffers

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Dakmor Sorceress

Dakmor Sorceress's power is equal to the number of Swamps you control.

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.