Mite Overseer

First strike
As long as it's your turn, creature tokens you control get +1/+0 and have first strike.
{3}{W/P}: Create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block." (Players dealt combat damage by it also get a poison counter. {W/P} can be paid with either {W} or 2 life.)

Annex Sentry

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Annex Sentry enters the battlefield, exile target artifact or creature an opponent controls with mana value 3 or less until Annex Sentry leaves the battlefield.

The Argent Etchings

(As this Saga enters and after your draw step, add a lore counter.)
I — Incubate 2 five times, then transform all Incubator tokens you control.
II — Creatures you control get +1/+1 and gain double strike until end of turn.
III — Destroy all other permanents except for artifacts, lands, and Phyrexians. Exile The Argent Etchings, then return it to the battlefield (front face up).

Elesh Norn

Vigilance
Whenever a source an opponent controls deals damage to you or a permanent you control, that source's controller loses 2 life unless they pay {1}.
{2}{W}, Sacrifice three other creatures: Exile Elesh Norn, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Elesh Norn // The Argent Etchings

Borrowed Time

When Borrowed Time enters the battlefield, exile target nonland permanent an opponent controls until Borrowed Time leaves the battlefield.

In the Trenches

Creatures you control get +1/+1.
{5}{W}: Exile target nonland permanent you don't control until In the Trenches leaves the battlefield. Activate only as a sorcery and only once.

Basilica Shepherd

Flying
When Basilica Shepherd enters the battlefield, create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Charge of the Mites

Choose one —
• Charge of the Mites deals damage equal to the number of creatures you control to target creature or planeswalker.
• Create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Crawling Chorus

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Crawling Chorus dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature enters the battlefield under your control, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Mirrex

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if Mirrex entered the battlefield this turn.
{3}, {T}: Create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block." (Players dealt combat damage by it also get a poison counter.)

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Welcoming Vampire

Flying
Whenever one or more other creatures with power 2 or less enter the battlefield under your control, draw a card. This ability triggers only once each turn.

Intrepid Adversary

Lifelink
When Intrepid Adversary enters the battlefield, you may pay {1}{W} any number of times. When you pay this cost one or more times, put that many valor counters on Intrepid Adversary.
Creatures you control get +1/+1 for each valor counter on Intrepid Adversary.

Skrelv's Hive

At the beginning of your upkeep, you lose 1 life and create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."
Corrupted — As long as an opponent has three or more poison counters, creatures you control with toxic have lifelink.

Plains

Crystal Grotto

When Crystal Grotto enters the battlefield, scry 1.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering the battlefield don't cause abilities of permanents your opponents control to trigger.

The Fair Basilica

The Fair Basilica enters the battlefield tapped.
{T}: Add {W}.
{1}{W}, {T}, Sacrifice The Fair Basilica: Draw a card.

Tocasia's Welcome

Whenever one or more creatures with mana value 3 or less enter the battlefield under your control, draw a card. This ability triggers only once each turn.

White Sun's Twilight

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)

Mondrak, Glory Dominus

If one or more tokens would be created under your control, twice that many of those tokens are created instead.
{1}{W/P}{W/P}, Sacrifice two other artifacts and/or creatures: Put an indestructible counter on Mondrak, Glory Dominus. ({W/P} can be paid with either {W} or 2 life.)