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.

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Northern Express Line enters tapped.
{T}: Add {U}.

Northrime Aurora enters tapped unless you played it from exile.
{T}: Add {G} or {U}.

{T}: Add {C}.
{3}{W}, {T}: Create a 1/1 white Peasant creature token.
Whenever you attack with five or more creatures, you may pay {1}{W}{W} and exile this land. When you do, attacking creatures get +1/+1 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
Whenever Novaheart Dragon enters or attacks, you may take an extra turn after this one. If you do, you lose the game at the beginning of that turn's end step.

Flying
When Novaheart Guardian enters, it deals 4 damage to any target.
Whenever a creature or planeswalker dies, put a +1/+1 counter on Novaheart Guardian.

Flying
Whenever Novean Sky Swallower blocks or becomes blocked by a creature with flying, destroy that creature, then put a +1/+1 counter on Novean Sky Swallower.

Noxan Altar enters tapped.
{T}: Add {W} or {B}.
{W}{B}, {T}, Tap an untapped creature you control: Create a Function token with “Lifelink.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Reverberate—Sacrifice a Swamp. (When you cast this spell, copy it if you paid its reverberate cost.)
All creatures get -2/-2 until end of turn.

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.)

Abilities of creatures you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: Target creature gains haste 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.”

Flash
Whenever Nsimi's Scrambler deals combat damage to a player, look at that player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

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.

Activated abilities of other permanents cost an additional “Sacrifice a permanent” to activate unless they're mana abilities.
{2}, {T}, Sacrifice Nullifier of Planar Energy: Remove all counters from target nonland permanent.

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

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

Menace
When OM-6 Walker dies, OM-6 Walker deals damage to each player equal to twice the number of nonbasic lands that player controls.

Whenever a creature you control dies, Oakpoint gets +4/+0 until end of turn.

Trample
Assault {1}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, draw a card.

This spell costs {1} less to cast for each card you've drawn this turn.
You may reveal a land card from outside the game and put it into your hand. If it's basic or a Desert, put it into the battlefield instead.

Search your library for a nongreen creature card with mana value X or less and put that card onto the battlefield, then shuffle. That creature 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.)

At the beginning of your end step, judge target creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)