msem-instigator

Whenever you sacrifice one or more permanents, put a +1/+1 counter on Marsh Dweller.

Target creature gains hexproof until end of turn.
Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

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.)

Flying

Target creature gets +1/+1 until end of turn. Then draw a card if that creature is a Warrior.

{T}: Add one mana of any color.

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.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Martoob Watershaper enters, tap target creature. It doesn't untap during its controller's next untap step.

{1}, Sacrifice Martyr of the Work: Purge. (Exile two cards that share a type from graveyards. If you do, draw a card.)

Whenever an attacking creature your team controls dies, you gain 3 life.

As an additional cost to cast this spell, discard a card at random.
Draw three cards.

First strike

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}: Look at the top card of your library. You may put the card back or into your graveyard.

{T}: Add {C}.
Whenever you tap Masamori Initiate for mana, you may mill a card.

Art of war — At the beginning of your end step, if Masamori Ranger dealt damage to an opponent this turn, search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sacrifice a creature: Put a +1/+1 counter on Masked Assailant. It gains menace until end of turn. Activate only as a sorcery.

Flying
When Masked Stalker enters, target player discards a card.

When Mass Orator enters, if it isn't a token, populate. (Create a token that's a copy of a creature token you control.)
Creature tokens you control get +1/+1.

When Master Chef enters, create a 0/1 green Plant creature token.
Sacrifice a Plant: You gain 3 life.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Master of Ancient Ways mentors a creature, that creature gains double strike until end of turn.

Whenever an artifact you control enters, Master of Munitions deals 1 damage to each opponent.

Enchant creature
Enchanted creature has defender.

Enchant creature
Enchanted creature gets +1/+1.
{W}: Enchanted creature gains vigilance until end of turn.
{1}{W}: Enchanted creature gains first strike until end of turn.

Target creature you control gets +1/+0 until end of turn. It fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)