Basalt Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap this artifact.

Doomsday

Search your library and graveyard for five cards and exile the rest. Put the chosen cards on top of your library in any order. You lose half your life, rounded up.

Dualcaster Mage

Flash
When this creature enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Bog Initiate

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate this creature.

Kess, Dissident Mage

Flying
Once during each of your turns, you may cast an instant or sorcery spell from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Demonic Gifts

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield under its owner's control."

Dark Ritual

Jet Medallion

Black spells you cast cost {1} less to cast.

Saw in Half

Destroy target creature. If that creature dies this way, its controller creates two tokens that are copies of that creature, except their power is half that creature's power and their toughness is half that creature's toughness. Round up each time.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Cormela, Glamour Thief

Haste
{1}, {T}: Add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.
When Cormela dies, return up to one target instant or sorcery card from your graveyard to your hand.

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Kokusho, the Evening Star

Flying
When Kokusho dies, each opponent loses 5 life. You gain life equal to the life lost this way.