Urborg, Tomb of Yawgmoth

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

Xiahou Dun, the One-Eyed

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Sacrifice Xiahou Dun, the One-Eyed: Return target black card from your graveyard to your hand. Activate only during your turn, before attackers are declared.

Kormus Bell

All Swamps are 1/1 black creatures that are still lands.

Balthor the Defiled

Minion creatures get +1/+1.
{B}{B}{B}, Exile Balthor the Defiled: Each player returns all black and all red creature cards from their graveyard to the battlefield.

Sins of the Past

Until end of turn, you may cast target instant or sorcery card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead. Exile Sins of the Past.

Exsanguinate

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

The Prismatic Bridge

At the beginning of your upkeep, reveal cards from the top of your library until you reveal a creature or planeswalker card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Esika, God of the Tree

Vigilance
{T}: Add one mana of any color.
Other legendary creatures you control have vigilance and "{T}: Add one mana of any color."

Esika, God of the Tree // The Prismatic Bridge

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

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.

Planar Birth

Return all basic land cards from all graveyards to the battlefield tapped under their owners' control.

Diabolic Revelation

Search your library for up to X cards, put those cards into your hand, then shuffle.

Swamp

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Command the Dreadhorde

Choose any number of target creature and/or planeswalker cards in graveyards. Command the Dreadhorde deals damage to you equal to the total mana value of those cards. Put them onto the battlefield under your control.