Fear
: This creature gets +1/+1 until end of turn.

This land enters tapped.
When this land enters, surveil 1.

: Create a Treasure token. Activate only if a creature died this turn.

When this creature enters, you may sacrifice another creature. If you do, put two +1/+1 counters on this creature, then scry 2.

Whenever a creature deals combat damage to a player, its controller may draw a card.

Whenever chaos ensues, you have no maximum hand size for the rest of the game.

Target opponent discards a card. Then they may discard an additional card. If they don't, conjure a duplicate of a random card from their library into your hand. It perpetually gains "You may spend mana as though it were mana of any color to cast this spell."

Target player loses 1 life, discards a card, then sacrifices a permanent of their choice.
Cipher

, Sacrifice another creature: Put a +1/+1 counter on this creature. It gains menace until end of turn. Activate only as a sorcery.

, Sacrifice a creature: Target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

When this creature enters, you may sacrifice an artifact or creature. When you do, exile target creature an opponent controls.

Rat Tail — When this creature dies, create a Treasure token.

You can't enter this dungeon unless you "venture into Undercity."

Secret Entrance — Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (=> Forge or Lost Well)

Forge — Put two +1/+1 counters on target creature. (=> Trap! or Arena)

Lost Well — Scry 2. (=> Arena or Stash)

Trap! — Target player loses 5 life. (=> Archives)

Arena — Goad target creature. (=> Archives or Catacombs)

Stash — Create a Treasure token. (=> Catacombs)

Archives — Draw a card. (=> Throne of the Dead Three)

Catacombs — Create a 4/1 black Skeleton creature token with menace. (=> Throne of the Dead Three)

Throne of the Dead Three — Reveal the top ten cards of your library. Put a creature card from among them onto the battlefield with three +1/+1 counters on it. It gains hexproof until your next turn. Then shuffle.

When this enchantment enters, you take the initiative.
Whenever you attack, if you or a player you're attacking has the initiative, you create two 1/1 white Soldier creature tokens that are tapped and attacking.

Whenever this creature enters or dies, create a 1/1 green Saproling creature token.
: Add one mana of any color.

Deathtouch
When Underbridge Warlock enters, you get a one-time boon with "At the beginning of your end step, if three or more creatures died this turn, each opponent loses 5 life and you gain 5 life."
At the beginning of your end step, if you have a boon, you mill three cards, draw a card, and lose 2 life.

Manifest dread.
You may return a permanent card from your graveyard to your hand.

Zombie spells you cast cost less to cast.
Zombie creatures you control get +2/+1.

Trample, haste
You may cast this card from your graveyard if a non-Zombie creature died this turn. If you do, this creature enters with a +1/+1 counter on it.

, : Exile target Skeleton, Vampire, or Zombie.

When this creature enters, create a 2/2 black Zombie creature token for each card named Undead Servant in your graveyard.

: This creature gets +1/-1 until end of turn.
Unearth

Deathtouch
Whenever one or more creature cards leave your graveyard, each opponent loses 1 life and you gain 1 life.

, Discard a card: Return this card from your graveyard to your hand. Activate only during your upkeep.
Cycling

When this creature dies, you may have target creature get -2/-2 until end of turn.

When this creature enters, mill three cards.
When this creature dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

Whenever this creature or another Zombie you control dies, you draw a card and you lose 1 life.