Oswald Fiddlebender

Magical Tinkering — {W}, {T}, Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Arborea Pegasus

Flying
When Arborea Pegasus enters, target creature gets +1/+1 and gains flying until end of turn.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Spiked Pit Trap

Flash
{5}, {T}, Sacrifice Spiked Pit Trap: Choose target creature, then roll a d20.
1—9 | Spiked Pit Trap deals 5 damage to that creature.
10—20 | Spiked Pit Trap deals 5 damage to that creature. Create a Treasure token.

+2 Mace

Equipped creature gets +2/+2.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Gloom Stalker

As long as you've completed a dungeon, Gloom Stalker has double strike.

Zombie Ogre

At the beginning of your end step, if a creature died this turn, venture into the dungeon. (Enter the first room or advance to the next room.)

Fates' Reversal

Return up to one target creature card from your graveyard to your hand. Venture into the dungeon. (Enter the first room or advance to the next room.)

Mimic

{T}, Sacrifice Mimic: Add one mana of any color.
{2}: Mimic becomes a Shapeshifter artifact creature with base power and toughness 3/3 until end of turn.

Spare Dagger

Equipped creature gets +1/+0 and has "Whenever this creature attacks, you may sacrifice Spare Dagger. When you do, this creature deals 1 damage to any target."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Swamp

Potion of Healing

When Potion of Healing enters, draw a card.
{W}, {T}, Sacrifice Potion of Healing: You gain 3 life.

Black Dragon

Flying
Acid Breath — When Black Dragon enters, target creature an opponent controls gets -3/-3 until end of turn.

Thieves' Tools

When Thieves' Tools enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equipped creature can't be blocked as long as its power is 3 or less.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Grim Bounty

Destroy target creature or planeswalker. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Precipitous Drop

Enchant creature
When Precipitous Drop enters, venture into the dungeon. (Enter the first room or advance to the next room.)
Enchanted creature gets -2/-2. It gets -5/-5 instead as long as you've completed a dungeon.

Yuan-Ti Fang-Blade

Deathtouch
Whenever Yuan-Ti Fang-Blade deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Lolth, Spider Queen

Whenever a creature you control dies, put a loyalty counter on Lolth, Spider Queen.
0: You draw a card and you lose 1 life.
−3: Create two 2/1 black Spider creature tokens with menace and reach.
−8: You get an emblem with "Whenever an opponent is dealt combat damage by one or more creatures you control, if that player lost less than 8 life this turn, they lose life equal to the difference."

Planar Ally

Flying
Whenever Planar Ally attacks, venture into the dungeon. (Enter the first room or advance to the next room.)

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Manticore

Flash
Flying
Tail Spikes — When Manticore enters, destroy target creature an opponent controls that was dealt damage this turn.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Treasure Chest

{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Clattering Skeletons

When Clattering Skeletons dies, venture into the dungeon. (Enter the first room or advance to the next room.)

Sepulcher Ghoul

Sacrifice another creature: Sepulcher Ghoul gets +2/+2 until end of turn. Activate only once each turn.

Shambling Ghast

When Shambling Ghast dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Asmodeus the Archfiend

Binding Contract — If you would draw a card, exile the top card of your library face down instead.
{B}{B}{B}: Draw seven cards.
{B}: Return all cards exiled with Asmodeus the Archfiend to their owner's hand and you lose that much life.

Paladin's Shield

Flash
When Paladin's Shield enters, attach it to target creature you control.
Equipped creature gets +0/+2.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Drider

Reach
Whenever Drider deals combat damage to a player, create a 2/1 black Spider creature token with menace and reach.

Reaper's Talisman

Whenever equipped creature attacks, it gains deathtouch until end of turn.
Whenever equipped creature attacks alone, defending player loses 2 life and you gain 2 life.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Cloister Gargoyle

When Cloister Gargoyle enters, venture into the dungeon. (Enter the first room or advance to the next room.)
As long as you've completed a dungeon, Cloister Gargoyle gets +3/+0 and has flying.

Dungeon Crawler

Dungeon Crawler enters tapped.
Whenever you complete a dungeon, you may return Dungeon Crawler from your graveyard to your hand.

Dawnbringer Cleric

When Dawnbringer Cleric enters, choose one —
• Cure Wounds — You gain 2 life.
• Dispel Magic — Destroy target enchantment.
• Gentle Repose — Exile target card from a graveyard.

Lightfoot Rogue

Sneak Attack — Whenever Lightfoot Rogue attacks, roll a d20.
1—9 | Lightfoot Rogue gains deathtouch until end of turn.
10—19 | It gets +1/+0 and gains deathtouch until end of turn.
20 | It gets +3/+0 and gains first strike and deathtouch until end of turn.