msem-instigator

At the beginning of your end step, you may discard a creature card. If you do, you draw a card and you lose 1 life.
Whenever a creature you control attacks alone, you may cast a creature card from your graveyard. That creature enters tapped and attacking. If you do, sacrifice the creature you attacked with at end of combat.

(Activate each ability only once as a sorcery. You gain the realm's favor after activating them all.)
{W}: Put a first strike counter on target creature.
{1}{W}: Invigorate 2. (Choose a creature with the least power among creatures you control and put two +1/+1 counters on it.)
{2}{W}: Create two 1/1 white Soldier creature tokens.
Creatures you control with counters on them have flying and lifelink.

Flying, haste
At the beginning of each of your postcombat main phases, you may cast an instant or sorcery card from your graveyard with mana value less than or equal to the number of creatures that dealt combat damage to opponents this turn without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

You may have Imitator of Success enter as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

Whenever you cast a noncreature spell, upgrade Indecisive Sorceress. When you can't, remove all counters from it and it deals damage to any target equal to the number of counters removed this way.
• +1/+1
• Flying
• First strike

Sacrifice two lands, Mill five cards: Return Jack, Horrific Harvester from your graveyard to your hand.
[+1]: You gain 2 life and each opponent loses 2 life.
[–2]: Return up to one target creature card and up to one target land card from your graveyard to your hand.
[–2]: Each opponent sacrifices the nonland permanent they control with the greatest mana value among permanents they control.

{1}{U}{B}, Discard Karaja Hetegex: You may activate one of her loyalty abilities without paying its loyalty cost.
[–1]: Return target artifact, enchantment, or spell to its owner's hand.
[–1]: Target creature gets -2/-2 until end of turn.
[–1]: Scry 1, then draw a card.

Deception {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever King Florence of Caulder enters or attacks, torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Whenever you cast a spell with mana value greater than the number of loyalty counters on Kunal, Dragonclaw's Legacy, put a loyalty counter on him.
[0]: Until end of turn, Kunal becomes a Monk creature with haste, indestructible, and “Kunal's base power and toughness are each equal to the number of counters on him.”
[–2]: Return target card from your graveyard to your hand.

Lifelink
If a creature or planeswalker would die, instead exile it and put a +1/+1 counter on Librarian of Whispers.

Flying
Whenever another creature you control enters, you may search your library for an instant or sorcery card with the same mana value as that creature, reveal it, put it into your hand, then shuffle.

Double strike, vigilance
Whenever Major Benjamin Stout enters, attacks, or dies, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Counter target spell. If a permanent spell is countered this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Menace
Whenever one or more creature cards leave your graveyard, put a +1/+1 counter on Mausoleum Resident. It gains lifelink until end of turn.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
[+2]: Exile the top two cards of your library. Until end of turn, you may play one card exiled with this permanent.
[+1]: Exile up to two cards from your hand, then draw that many cards.
[–3]: Menna, Servant to None deals 3 damage to up to one target player and up to one target creature or planeswalker.

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. If that creature has flying, transform Mounting Up.

Choose one or both—
• Target creature gets -4/-4 until end of turn.
• Return target creature card with mana value 1 from your graveyard to the battlefield.

Create a token that's a copy of target permanent you control, except it isn't legendary. Then put Picture Perfect on the bottom of its owner's library if you cast it from exile.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

[+1]: Create a 1/1 green Merfolk creature token.
[0]: Target artifact or creature loses all abilities and becomes a green Seal creature with base power and toughness 3/3.
[–6]: Up to five target noncreature permanents lose all abilities and become green Merfolk creatures with base power and toughness 1/1.

First strike
Other creatures you control have protection from mana value 3 or greater.

This spell costs {1} less to cast for each instant and/or sorcery card in your graveyard.
Once each turn, when you cast an instant or sorcery spell, you may create a 4/4 white Angel Cleric creature token with flying and vigilance.

{T}: Add {C}.
{1}: Risti Workshop becomes a creature in addition to its other types until end of turn.
When Risti Workshop deals combat damage to an opponent, you may sacrifice it. If you do, search your library for a basic land card, put it onto the battlefield, then shuffle.

Whenever S-40 Wallbreaker attacks, create a 1/1 colorless Construct artifact creature token.
{X}, Sacrifice X artifacts: S-40 Wallbreaker deals X damage to each opponent.

When Snagged Truck enters, investigate three times. (Create three colorless Clue artifact tokens with “{2}, Sacrifice this: Draw a card.”)
Snagged Truck can't attack or block as long as you control a Clue.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Reveal cards from the top of your library until you reveal a land card, then put that card onto the battlefield tapped. You may put another card revealed this way on top of your library. Put the rest of the cards revealed this way on the bottom in a random order.