Sanguine Morass

Sanguine Morass enters the battlefield tapped.
{T}: Add {B} or {R}.

Bloodsoaked Insight

This spell costs {1} less to cast for each 1 life your opponents have lost this turn.
Target opponent exiles the top three cards of their library. Until the end of your next turn, you may play those cards. If you cast a spell this way, mana of any type can be spent to cast it.

Bloodsoaked Insight // Sanguine Morass

Yes Man, Personal Securitron

{T}: Target opponent gains control of Yes Man, Personal Securitron. When they do, you draw two cards and put a quest counter on Yes Man. Activate only during your turn.
Wild Card — When Yes Man leaves the battlefield, its owner creates a tapped 1/1 white Soldier creature token for each quest counter on it.

Simulacrum Synthesizer

When Simulacrum Synthesizer enters the battlefield, scry 2.
Whenever another artifact with mana value 3 or greater enters the battlefield under your control, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Worldwalker Helm

If you would create one or more artifact tokens, instead create those tokens plus an additional Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")
{1}{U}, {T}: Create a token that's a copy of target artifact token you control.

Hideous Taskmaster

Devoid
When you cast this spell, for each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain trample, haste, and annihilator 1 until end of turn.
Trample, haste, annihilator 1

We Ride at Dawn

Legendary creature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a legendary creature spell pays for {1} or one mana of that creature's color.)
Whenever your commander attacks, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Argent Dais

Argent Dais enters the battlefield with two oil counters on it.
Whenever two or more creatures attack, put an oil counter on Argent Dais.
{2}, {T}, Remove two oil counters from Argent Dais: Exile another target nonland permanent. Its controller draws two cards.

Witch-Blessed Meadow

As Witch-Blessed Meadow enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {W}.

Witch Enchanter

When Witch Enchanter enters the battlefield, destroy target artifact or enchantment an opponent controls.

Witch Enchanter // Witch-Blessed Meadow

Ulamog, the Defiler

When you cast this spell, target opponent exiles half their library, rounded up.
Ward—Sacrifice two permanents.
Ulamog, the Defiler enters the battlefield with a number of +1/+1 counters on it equal to the greatest mana value among cards in exile.
Ulamog has annihilator X, where X is the number of +1/+1 counters on it.

Legion Stronghold

Legion Stronghold enters the battlefield tapped.
{T}: Add {R} or {W}.

Legion Leadership

Until end of turn, double target creature's power and it gains first strike.

Legion Leadership // Legion Stronghold

Path of Annihilation

Devoid (This card has no color.)
When Path of Annihilation enters the battlefield, create two 0/1 colorless Eldrazi Spawn creature tokens with "Sacrifice this creature: Add {C}."
Eldrazi you control have "{T}: Add one mana of any color."
Whenever you cast a creature spell with mana value 7 or greater, you gain 4 life.

Phlage, Titan of Fire's Fury

When Phlage enters the battlefield, sacrifice it unless it escaped.
Whenever Phlage enters the battlefield or attacks, it deals 3 damage to any target and you gain 3 life.
Escape—{R}{R}{W}{W}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Grist, the Plague Swarm

+1: Create a 1/1 black and green Insect creature token, then mill two cards. Put a deathtouch counter on the token if a black card was milled this way.
−2: Destroy target artifact or enchantment.
−6: For each creature card in your graveyard, create a token that's a copy of it, except it's a 1/1 black and green Insect.

Grist, Voracious Larva

Deathtouch
Whenever Grist, Voracious Larva or another creature enters the battlefield under your control, if it entered from your graveyard or you cast it from your graveyard, you may pay {G}. If you do, exile Grist, then return it to the battlefield transformed under its owner's control.

Grist, Voracious Larva // Grist, the Plague Swarm

Trickster's Elk

Bestow {1}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3.