msem-instigator

Flying
Whenever another creature enters the battlefield under your control, you gain 1 life.

(Transform this if it's not attached to a creature. Pay {1}{W} as a sorcery to unattach it.)
Enchant creature you control
Mount of Heroes's rider gets +2/+1.
Sacrifice Mount of Heroes: Counter target spell that targets you or Mount of Heroes's rider.

Creatures you control get +2/+2 and gain first strike until end of turn.

Vanishing 3 (This permanent enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a creature dies or a time counter is removed from Mourn the Lost, you may tap target creature.

When Mourners of Mervin enters the battlefield, you may sacrifice a creature or enchantment. If you do, creatures you control get +1/+1 and gain vigilance until end of turn.

Players can't get counters.
Counters can't be put on permanents.

Create two 1/1 white Soldier creature tokens. Prevent all damage that would be dealt to them this turn.

Return a permanent you control to its owner's hand.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Choose one —
• Return target artifact or enchantment card from your graveyard to your hand.
• Return target creature card with mana value 2 or less from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform it.)
When Mystery of the Dying Herds enters the battlefield, create a 0/2 white Ox creature token.
I — A creature you control dies.
II — You have 4 or more life than your starting life total.

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

Vigilance (Attacking doesn't cause this creature to tap.)

Exile target permanent you control, then return that card to the battlefield under your control.

Look at the top seven cards of your library. You may reveal an Avatar card and/or an enchantment card from among them and put those cards onto the battlefield. Put the rest on the bottom of your library in any order.

Whenever Neo-Soul Attendant or another enchantment enters the battlefield under your control, you gain 1 life.

Whenever you gain life, put a +1/+1 counter on Neo-Soul Envoy.

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

Whenever New Alores Charmer attacks, you may tap target creature.

Harmony — You gain 2 life.
When New Alores Fiddler enters the battlefield, harmonize. (Trigger up to one harmony of one permanent you control.)

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.) [2/2]
[Lore I-II] You gain 1 life.
[Lore III] Target creature you control gains first strike until end of turn.

Flash
{1}{W}: Return Nimble Explorer to its owner's hand.

Flying
Sacrifice Nimbus Glider: Creatures you control gain flying until end of turn.

At the beginning of combat on your turn, you may attach target Equipment you control to Nina, Master of Arms.
Whenever Nina attacks, the next artifact spell you cast this turn costs {R/W}{R/W} less to cast. (This can reduce the amount of generic mana you pay.)

Flash
When Nixie's Edict enters the battlefield, tap up to two target creatures.
{2}{W}, Sacrifice Nixie's Edict: Put up to one target creature into its owner's library second from the top. Activate only as a sorcery.