msem-instigator

(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.

Return up to one target creature card from your graveyard to the battlefield tapped. You gain 2 life.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

Once each turn, when a creature you control attacks alone, you may untap target attacking creature. After this combat, there's an additional combat step.

Target creature gets +1/+1 until end of turn.
Fabled {2}{R/W}{R/W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Forlorn Path enters tapped unless you control one or fewer other lands.
{T}: Add {B} or {G}.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When A Matricide Most Foul enters or is defeated, each opponent exiles a permanent they control with the highest mana value among nonland permanents they control.

Menace
{1}{B}, Exile another three cards from your graveyard: Return Determined Explorer from your graveyard to your hand.

Equipped creature gets +0/+2 and has menace.
Equip {1}

Flying
Whenever another creature with flying you control enters, put a +1/+1 counter on Moonlight Strix.

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Young Tempter enters, you draw a card and you lose 1 life.

Flying, haste
At the beginning of the end step, sacrifice Brightflame Phoenix.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

When Heroic Aspiration enters, you may search your library for a creature card with an Adventure, reveal it, put it into your hand, then shuffle.
At the beginning of your end step, if you cast both a creature spell and a noncreature spell this turn, Heroic Aspiration deals 2 damage to each opponent and you gain 2 life.

{2}{U}: Target creature can't be blocked this turn.

Choose any target. Change the text of target instant or sorcery spell to “This spell deals 3 damage to the chosen target. Draw a card.”

When this creature dies, put a -1/-1 counter on up to one target creature.

CySec Infiltrator can't be blocked except by enchantment creatures.
Whenever CySec Infiltrator attacks, create a Function token with “Target player loses 2 life and you gain 2 life.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Vanishing 2 (This permanent enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
{T}: Add {C}.
When Unstable Footing is put into your graveyard from the battlefield, if it had no time counters on it, search your library for a basic land card, put it onto the battlefield, then shuffle.

Counter target spell unless its controller pays {2}.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

When Piruz, the Fourth Shah enters, discard your hand. For each creature card discarded this way, create a 3/3 black Demon creature token with flying. For each other card discarded this way, you gain 3 life.
Monument {5}{B}{B} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

{T}: Add {C}.
{T}, Sacrifice a creature: Add one mana of any color.

Exile target creature. Its controller may profit. (To profit, create a colorless Gold artifact token with “Sacrifice this artifact: Add one mana of any color.”)

Destroy target creature. You gain 1 life for each card in its controller's graveyard.

Whenever Haunting Maestro attacks, you may tap or untap up to two target creatures.