Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Deathbringer Thoctar

Whenever another creature dies, you may put a +1/+1 counter on Deathbringer Thoctar.
Remove a +1/+1 counter from Deathbringer Thoctar: It deals 1 damage to any target.

Junktroller

Defender
{T}: Put target card from a graveyard on the bottom of its owner's library.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

Fire Prophecy

Fire Prophecy deals 3 damage to target creature. You may put a card from your hand on the bottom of your library. If you do, draw a card.

Epitaph Golem

{2}: Put target card from your graveyard on the bottom of your library.

Judith, the Scourge Diva

Other creatures you control get +1/+0.
Whenever a nontoken creature you control dies, Judith, the Scourge Diva deals 1 damage to any target.

Reito Sentinel

Defender
When Reito Sentinel enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)
{3}: Put target card from a graveyard on the bottom of its owner's library.

Ashnod's Altar

The Cauldron of Eternity

This spell costs {2} less to cast for each creature card in your graveyard.
Whenever a creature you control dies, put it on the bottom of its owner's library.
{2}{B}, {T}, Pay 2 life: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Canal Dredger

Draft Canal Dredger face up.
Each player passes the last card from each booster pack to a player who drafted a card named Canal Dredger.
{T}: Put target card from your graveyard on the bottom of your library.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Workhorse

Workhorse enters with four +1/+1 counters on it.
Remove a +1/+1 counter from Workhorse: Add {C}.

Braid of Fire

Cumulative upkeep—Add {R}. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Grenzo, Dungeon Warden

Grenzo, Dungeon Warden enters with X +1/+1 counters on it.
{2}: Put the bottom card of your library into your graveyard. If it's a creature card with power less than or equal to Grenzo's power, put it onto the battlefield.