msem-instigator

When Marshal of Brethren enters, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Lionize {1}{G} ({1}{G}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
This creature assigns combat damage equal to its toughness rather than its power.

Lionize {2}{U} ({2}{U}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
Whenever this creature deals combat damage to a player, draw that many cards.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Vigilance
Martoob of Flowing Life has ward {X}, where X is the number of counters on her.
{G}{U}: Angel — Put a +1/+1 counter on each other creature you control.
{2}{G}{U}: Elder — Double the number of counters on permanents you control.

Flash
You may cast Angel and Nephilim spells as though they had flash.

Master Assassin can't be blocked by creatures with odd mana values. (Zero is even. This creature's mana value is 2.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Master Assassin. You may have it phase out.

{W}{B}, Pay X life: Return target creature card with mana value X from your graveyard to the battlefield with a finality counter on it. Activate only as a sorcery and only once each turn.
{W}{B}, Pay 3 life: Return Mehr's Last Captain from your graveyard to the battlefield with a finality counter on it.

If you would create an Army token while Mehr's Unending Horde is in your graveyard, you may instead return Mehr's Unending Horde from your graveyard to the battlefield.
Counters remain on Mehr's Unending Horde as it moves to any zone other than a player's hand or library.

When Nephilim Wisdomancer enters, mill three cards. Then you may pay {W}{B}. If you do, return a nonland card from your graveyard to your hand.

Whenever a land you control enters, put a +1/+1 counter on Nimble Pathfinder.
Surpass {5}{G} ({5}{G}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

As Nizev Fortress enters, you may pay 1 life. If you don't, Nizev Fortress enters tapped.
Satrapies you control have “{T}: Add {U}.”

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Nizev Rising enters, return target instant or sorcery card from your graveyard to your hand.

If another creature with a +1/+1 counter on it you control would die, instead remove a counter from it. If you do, it phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Flying
Whenever you cast a noncreature spell, you may exchange control of it and target creature. Then the spell's controller may choose new targets for it.

As an additional cost to cast this spell, sacrifice a permanent.
Draw two cards.

Return target creature card from your graveyard to the battlefield tapped. Then create a token that's a copy of it, except it has haste. Sacrifice the token at the beginning of the next end step.

Trample
Whenever Openmaw Demon or another Azra or Demon you control enters, you may exile target card from a graveyard.

Whenever Optimistic Chronicler deals damage to a player or noncreature permanent, surveil 1, then draw a card.

Menace
At the beginning of your end step, if a player lost 3 or more life this turn, put a +1/+1 counter on target Azra or Demon you control.

Whenever you sacrifice a permanent, Overseer of Armies deals 1 damage to each opponent and each battle they protect.

At the beginning of combat on your turn, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)
Armies you control have flying and lifelink.

Sacrifice any number of permanents. If five colors were among the sacrificed permanents, each player exiles the top five cards of their library. For each player, you may cast up to two cards they exiled this way without paying their mana costs.

Paygan Firebinder gets +1/+0 for each Satrapy you control.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

This spell costs {1} less to cast for each Angel and/or Nephilim you control.
Draw X cards.

When Persecutor of Truths enters, return target creature card with mana value 2 or less from your graveyard to the battlefield.
Once each turn, when you cast a spell from anywhere other than your hand or another nontoken creature you control enters and wasn't cast, you may draw a card.