msem-instigator

At the beginning of your end step, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Equipped creature gets +2/+2 and has hexproof and vigilance.
Equip {2}

At the beginning of combat on your turn, gain control of another target permanent until end of turn. Untap that permanent. It gains haste until end of turn.
Fleeting {2}{R}{R} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Play with the top card of your library revealed.
You may cast creature spells from the top of your library. You may cast Centaur spells this way without paying their mana costs.

At the beginning of your end step, if you gained life this turn, you gain 2 life.
Pay 3 life: Target attacking creature gains indestructible until end of turn.

As Soli Fortress enters, you may pay 1 life. If you don't, Soli Fortress enters tapped.
Satrapies you control have “{T}: Add {W}.”

When Aridland Camaar enters, create a 1/1 white Bird creature token with flying.

{B}{R}, {T}, Sacrifice Heretical Soulshifter: Return target creature card from your graveyard to the battlefield. It gains haste until end of turn. Activate only as a sorcery.

Whenever Moonlit Lurker blocks, put a +1/+1 counter on it.

Flying, haste
Whenever Grieving Revenant attacks, it deals 1 damage to each other creature you control.

(Add a quest counter as this enters. Sacrifice after 3.)
1, 2 — Whenever you attack with one or more creatures with power 4 or greater, add a quest counter.
3 — Until end of turn, target creature you control gains trample and “Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.”
Put two +1/+1 counters on target creature you control. It fights up to one target creature you don't control.

At the beginning of your upkeep, if you have more life than an opponent, create a 1/1 black Insect Spirit creature token with flying.
{3}{B}: Each opponent loses X life and you gain X life, where X is the number of Clerics you control.

Poisonous 3 (Whenever this creature deals combat damage to a player, that player gets three poison counters.)
When Soulbreaker of Mautakesh enters, target poisoned player sacrifices a creature.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you cast your first spell outside your main phase each turn, add a quest counter.
1, 2 — Draw cards equal to the number of quest counters on Siltbottom Expedition, then discard that many cards.
3 — Put up to two target instant or sorcery cards from your graveyard on top of your library in any order, then draw a card.

Whenever Crescent Crasher attacks, put a +1/+1 counter on target attacking creature with lesser power.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Put a +1/+1 counter on each creature you control.
3 | Those creatures gain vigilance and deathtouch until end of turn.

When Sandwurm's Might enters, you may have target creature you control fight target creature you don't control.
Each creature you control enters with an additional +1/+1 counter on it.

Flash
{U}, Return another creature you control to its owner's hand: Reclusive Archmage can't be blocked this turn and gains hexproof until end of turn. Activate only once each turn.

Target opponent mills four cards. Scry 2.

Nonbasic lands target player controls don't untap during that player's next untap step.
Fabled {3}{R} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Destroy target creature with power, toughness, or mana value 4 or greater.

Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has haste.

({T}: Add {W} or {B}.)
As Blessed Mausoleum enters, you may pay {1}. If you don't, Blessed Mausoleum enters tapped.