msem-instigator

Lifelink
If a source would deal damage to a player, you may prevent X of that damage, where X is the number of +1/+1 counters on Mending Caretaker.

Equipped creature gets +0/+4.
Equip {2}

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Exile the top three cards of your library. Cast a spell with mana value X or less from among them without paying its mana cost.

Flash
When Mighty Beetle enters, you may put two +1/+1 counters on target creature you control.

({T}: Add {G} or {U}.)
Monsoon Lagoon enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Vanguard — Whenever a creature you control attacks alone, that creature gets +3/+0 until end of turn.

Lifelink
At the beginning of your end step, you gain 1 life if you gained life this turn, and each opponent that lost life this turn loses 1 life.

Whenever you gain life, you may put target creature or planeswalker card from your graveyard on top of your library.

Put two +1/+1 or loyalty counters on target creature or planeswalker. It gains lifelink until end of turn.

Gain control of target creature until end of turn.
Coalesce {6}{U}{B} (You may cast this from your graveyard for {6}{U}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
As long as Mortal Whims Falter is on the battlefield, you can't lose control of permanents.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Whenever a land you control enters, put a +1/+1 counter on Mountain Runt, then it deals 1 damage to up to one target creature you don't control.
When Mountain Runt has three or more +1/+1 counters on it, remove them all and transform it.

Menace
At the beginning of your end step, Mountain Tyrant deals 1 damage to each creature you don't control.

First strike
Whenever a creature dealt damage by Mournful Newborn this turn dies, transform Mournful Newborn.

({T}: Add {U} or {B}.)
Muggy Mire enters tapped unless you control two or more basic lands.

Return target creature you control to its owner's hand. You gain life equal to its power.

Target player loses X life and you gain X life, where X is the number of permanents you control with counters on them.

Flying
At the beginning of your upkeep, mill seven cards, then you may cast an instant or sorcery card from your graveyard. If that spell would be put into your graveyard, exile it instead.
If you would draw a card while your library has no cards in it, you win the game instead.

Whenever an opponent discards a card, exile it. You may cast that card as long for as it remains exiled, and you may spend black mana as though it were mana of any color to cast that spell.

Flying
Whenever another creature enters, you gain 1 life.

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

{2}, {T}, Sacrifice Old Map: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Target creature gets -2/-2 until end of turn.
{3}{B}{B}, Exile Ominous Wind from your graveyard: Each creature gets -2/-2 until end of turn. Activate only as a sorcery.

Vanguard — Whenever a creature you control attacks alone, put a +1/+1 counter on it.

Spells your opponents cast that target Onigori, Ema's Shield cost {2} more to cast.
Whenever Onigori deals combat damage to a player, that player can't untap more than two permanents during their next untap step.