msem-instigator

At the beginning of your upkeep, germinate. Then if creatures you control have total power 10 or greater, transform Mushroom Merchant. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

You may have Mutalithic Golem enter as a copy of any land on the battlefield, except it's an artifact in addition to its other types.

First strike
When Mutilated Warrior enters, you may have it deal damage to each player equal to the number of Warriors you control.

Reverberate {2}{G} (When you cast this spell, copy it if you paid its reverberate cost. The copy becomes a permanent when it resolves.)
Mystical Echo gets +1/+1 for each other Reflection you control.
Whenever you discard a card, Reflections you control gain trample until end of turn.

{T}: Mystical Elk becomes a copy of target creature card in your graveyard. Activate only as a sorcery. (It loses this ability.)

When Mythos Scribe enters, you may return target storied card from your graveyard to your hand. (Enchantments and legendary permanents are storied.)

Haste
Whenever Nadei deals combat damage to a player, that player sacrifices a land. You may put a land card from a graveyard onto the battlefield under your control.

Flying
Whenever Naiala's Guide deals combat damage to a player, draw a card, then discard a card.

Nameless Throng can't block.
{1}{B}, Exile an artifact or enchantment card from your graveyard: Return Nameless Throng from your graveyard to the battlefield.

Flying
When Namuzzar's Iterator enters, you may return an artifact or enchantment you control to its owner's hand.

Reach
Whenever Nanowrought Vanguard attacks, put a +1/+1 counter on each enchantment creature you control.

Instant and sorcery spells you cast cost {1} less and an additional 1 life to cast.
You control your opponents while instant and sorcery spells you control are resolving.

Trial 2 (As you cast this spell, an opponent of your choice may pay 2 life. If they don't, they fail the trial.)
When Nascent Adversary enters, if the trial was failed, it gains haste and first strike until end of turn.

Vigilance
Mountaincycling {1}, plainscycling {1} ({1}, Discard this card: Search your libary for a Mountain or Plains card, reveal it, put it into your hand, then shuffle.)

Neckbreaker Viking gets +1/+0 and has menace as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Neo-Soul Naturalist enters, exile up to one target artifact or enchantment. Its controller conjures a card named Data-Point into their hand. (It's a sorcery that costs {2} with “Draw a card.”)

Whenever you discard a card, tap up to one target creature.

Whenever Neon Claw Knight enters or attacks, choose one. Create a Function token with that effect. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)
• This spell can't be countered.
• This spell costs {R} less to cast.
• If this spell would deal damage to a permanent or player, it deals that much damage plus 1 instead.

Flash
When Nephalia Inquisitors enters, draw a card for each creature that died this turn.

Flying
When Nest Matriarch enters, put a +1/+1 counter on another target creature you control. That creature gains lifelink until end of turn.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Each player loses 1 life.
[Lore III] Create a 1/1 black Harpy creature token with flying.

When Night Shepherd enters, return a creature you control to its owner's hand.