Kozilek's Channeler

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Homicidal Seclusion

As long as you control exactly one creature, that creature gets +3/+1 and has lifelink.

Swamp

Warden of Geometries

Vigilance
{T}: Add {C}. ({C} represents colorless mana.)

Ur-Golem's Eye

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Final Parting

Search your library for two cards. Put one into your hand and the other into your graveyard. Then shuffle.

Deepwood Legate

If an opponent controls a Forest and you control a Swamp, you may cast this spell without paying its mana cost.
{B}: Deepwood Legate gets +1/+1 until end of turn.

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice Crystal Vein: Add {C}{C}.

Phantasmagorian

When you cast this spell, any player may discard three cards. If a player does, counter Phantasmagorian.
Discard three cards: Return Phantasmagorian from your graveyard to your hand.

Ebon Stronghold

Ebon Stronghold enters tapped.
{T}: Add {B}.
{T}, Sacrifice Ebon Stronghold: Add {B}{B}.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Sisay's Ring

Lunar Avenger

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
Remove a +1/+1 counter from Lunar Avenger: Lunar Avenger gains your choice of flying, first strike, or haste until end of turn.

Mage-Ring Network

{T}: Add {C}.
{1}, {T}: Put a storage counter on Mage-Ring Network.
{T}, Remove any number of storage counters from Mage-Ring Network: Add {C} for each storage counter removed this way.

Makeshift Mannequin

Return target creature card from your graveyard to the battlefield with a mannequin counter on it. For as long as that creature has a mannequin counter on it, it has "When this creature becomes the target of a spell or ability, sacrifice it."

Peat Bog

Peat Bog enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from Peat Bog: Add {B}{B}. If there are no depletion counters on Peat Bog, sacrifice it.

Deadly Wanderings

As long as you control exactly one creature, that creature gets +2/+0 and has deathtouch and lifelink.

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Sultai Scavenger

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying

Lotus Guardian

Scour from Existence

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Endling

{B}: Endling gains menace until end of turn.
{B}: Endling gains deathtouch until end of turn.
{B}: Endling gains undying until end of turn. (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)
{1}: Endling gets +1/-1 or -1/+1 until end of turn.

Skirge Familiar

Geode Golem

Trample
Whenever Geode Golem deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Subterranean Hangar

Subterranean Hangar enters tapped.
{T}: Put a storage counter on Subterranean Hangar.
{T}, Remove any number of storage counters from Subterranean Hangar: Add {B} for each storage counter removed this way.

Razaketh's Rite

Search your library for a card, put that card into your hand, then shuffle.
Cycling {B} ({B}, Discard this card: Draw a card.)

Glacial Chasm

Cumulative upkeep—Pay 2 life. (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.)
When Glacial Chasm enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Hollow One

This spell costs {2} less to cast for each card you've cycled or discarded this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Cinderhaze Wretch

{T}: Target player discards a card. Activate only during your turn.
Put a -1/-1 counter on Cinderhaze Wretch: Untap Cinderhaze Wretch.

Unmask

You may exile a black card from your hand rather than pay this spell's mana cost.
Target player reveals their hand. You choose a nonland card from it. That player discards that card.