Azlask, the Swelling Scourge

Whenever Azlask, the Swelling Scourge or another colorless creature you control dies, you get an experience counter.
{W}{U}{B}{R}{G}: Creatures you control get +X/+X until end of turn, where X is the number of experience counters you have. Scions and Spawns you control gain indestructible and annihilator 1 until end of turn.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Catacomb Sifter

Devoid (This card has no color.)
When Catacomb Sifter enters, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."
Whenever another creature you control dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Eldrazi Confluence

Choose three. You may choose the same mode more than once.
• Target creature gets +3/-3 until end of turn.
• Exile target nonland permanent, then return it to the battlefield tapped under its owner's control.
• Create a 1/1 colorless Eldrazi Scion creature token with "Sacrifice this creature: Add {C}."

Otharri, Suns' Glory

Flying, lifelink, haste
Whenever Otharri, Suns' Glory attacks, you get an experience counter. Then create a 2/2 red Rebel creature token that's tapped and attacking for each experience counter you have.
{2}{R}{W}, Tap an untapped Rebel you control: Return Otharri from your graveyard to the battlefield tapped.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Minthara, Merciless Soul

Minthara has ward {X}, where X is the number of experience counters you have.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, you get an experience counter.
Creatures you control get +1/+0 for each experience counter you have.

Drowner of Hope

Devoid (This card has no color.)
When Drowner of Hope enters, create two 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this creature: Add {C}."
Sacrifice an Eldrazi Scion: Tap target creature.

Ezuri, Claw of Progress

Whenever a creature you control with power 2 or less enters, you get an experience counter.
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is the number of experience counters you have.

Propagator Drone

Devoid (This card has no color.)
Creature tokens you control have evolve. (They have "Whenever a creature you control enters, if it has greater power or toughness than this token, put a +1/+1 counter on this token." They see this creature enter.)
{3}{G}: Create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."

Glaring Fleshraker

Whenever you cast a colorless spell, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."
Whenever another colorless creature you control enters, Glaring Fleshraker deals 1 damage to each opponent.

Sire of Stagnation

Devoid (This card has no color.)
Whenever a land an opponent controls enters, that player exiles the top two cards of their library and you draw two cards.

Spawnbed Protector

At the beginning of your end step, return up to one target Eldrazi creature card from your graveyard to your hand. Create two 1/1 colorless Eldrazi Scion creature tokens with "Sacrifice this creature: Add {C}."

Emrakul's Messenger

Devoid (This card has no color.)
Flying
Whenever you draw your second card each turn, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."

Echoes of Eternity

If a triggered ability of a colorless spell you control or another colorless permanent you control triggers, that ability triggers an additional time.
Whenever you cast a colorless spell, copy it. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Smothering Abomination

Devoid (This card has no color.)
Flying
At the beginning of your upkeep, sacrifice a creature.
Whenever you sacrifice a creature, draw a card.

Chittering Dispatcher

Devoid (This card has no color.)
Myriad
When Chittering Dispatcher leaves the battlefield, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."

Kalemne, Disciple of Iroas

Double strike, vigilance
Whenever you cast a creature spell with mana value 5 or greater, you get an experience counter.
Kalemne, Disciple of Iroas gets +1/+1 for each experience counter you have.

Awakening Zone

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Daxos the Returned

Whenever you cast an enchantment spell, you get an experience counter.
{1}{W}{B}: Create a white and black Spirit enchantment creature token. It has "This creature's power and toughness are each equal to the number of experience counters you have."

Eyeless Watcher

Devoid (This card has no color.)
When Eyeless Watcher enters, create two 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this creature: Add {C}."

Path of Annihilation

Devoid (This card has no color.)
When Path of Annihilation enters, 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.

From Beyond

Devoid (This card has no color.)
At the beginning of your upkeep, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."
{1}{G}, Sacrifice From Beyond: Search your library for an Eldrazi card, reveal it, put it into your hand, then shuffle.

Oblivion Sower

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

Kozilek's Unsealing

Devoid (This card has no color.)
Whenever you cast a creature spell with mana value 4, 5, or 6, create two 0/1 colorless Eldrazi Spawn creature tokens with "Sacrifice this creature: Add {C}."
Whenever you cast a creature spell with mana value 7 or greater, draw three cards.

Sol Ring

Unfathomable Truths

Devoid (This card has no color.)
Draw three cards and create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."

Nulldrifter

When you cast this spell, draw two cards.
Flying
Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)