msem-instigator

This spell costs {X} less to cast, where X is half the number of creatures on the battlefield, rounded down.
Destroy all creatures.

When North Ward Settler enters, choose one —
• Create a 1/1 white Dwarf creature token.
• Put a +1/+1 counter on North Ward Settler.

As long as it's not your turn, Northrime Amalgam gets -2/+2.

When Norwick Barkeep enters, target creature you control gets +1/+1 and gains vigilance until end of turn.

At the beginning of your end step, create a tapped 1/1 colorless Human creature token.
Whenever you attack, put a loyalty counter on each planeswalker you control.

Flying, haste
You may reveal each card you draw as you draw it. Whenever you reveal a creature card with mana value 1 or less this way, create a token that's a copy of it. That copy gains haste until end of turn.

You may activate an additional loyalty ability of Nox during your turn as long as Nox or another enchantment you control has entered this turn.
[+1]: You gain life equal to the amount of life lost by target player this turn.
[0]: Target opponent loses 2 life. You gain 2 life.
[–2]: Exile target nonland permanent. You lose life equal to its mana value.

Prowess
Whenever you cast a noncreature spell, Noxan Pilgrim gains lifelink until end of turn.

[+1]: Until end of turn, up to one target creature gets +1/+0 and can't be blocked.
[–2]: Exile target artifact or enchantment.
[–5]: You get an emblem with “Untap all permanents you control during each other players untap step” and “Draw a card during each other player's draw step.”

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, target creature you control can't be blocked this turn.

Exile target permanent, then return it to the battlefield under its owner's control. If that permanent was an attacking creature, you may have it enter tapped and attacking.

Flash
When Nurse Trainee enters, you may prevent the next 2 damage that would be dealt to another target creature this turn.

Flying
Whenever you cast a creature spell for the first time each turn, create a 1/1 green Insect creature token.

Whenever an enchantment you control enters, draw a card. This ability triggers only once each turn.
As long as you control three or more enchantments, Nykthos Enchantress gets +2/+2 and has vigilance.

This spell costs {1} less to cast for each enchantment you control.
Destroy all creatures.

Flash
Enchant creature
Enchanted creature gets +2/+2.

Defender, first strike
{1}{G}: Oaken Spearman can attack this turn as though it didn't have defender.

Vigilance
When this creature dies, target creature you control seeks secrets or valor. (Give it that Oath Aura. Fulfill secrets by attacking with it and two or more other creatures to draw a card. Fulfill valor by dealing combat damage to a player to create a 2/1 white Soldier token.)

When Oathkeeper's Verdict enters, tap all creatures your opponents control.
Equipped creature gets +3/+3.
Equip {3}

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Observing Guardian enters, if tribute wasn't paid, create a 2/2 white Cat creature token.

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.

Motley — At the beginning of combat on your turn, if there are five or more names among nonland permanents you control, Ochre Knight gets +2/+1 until end of turn and you gain 1 life.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Concord — Once each turn, when an opponent casts a spell or activates an ability that targets a Merfolk or enchantment you control, you may counter that spell or ability if there are four or more card types among permanents you control.

Exile up to two target creatures controlled by different players. Return those creatures to the battlefield under their owners' control at the beginning of the next end step.

Flying
When Old-World Forgotten dies, you may return target artifact or enchantment card from your graveyard to your hand.