msem-instigator

Unbound Spirit can't be blocked.
When you attain Unbound Spirit, tap target creature. That creature doesn't untap during its controller's next untap step.

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
When Vedalken Reshaper enters, return target instant or sorcery card from your graveyard to your hand.

Whenever you cast a spell during an opponent's turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flying
Whenever Wandering Dragonfly or another creature you control enters, you may draw a card. If you do, discard a card.

Abomination Sculptor has deathtouch and lifelink as long as it's attacking.

{T}, Pay 1 life: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
At the beginning of your end step, if your life total is less than 5, sacrifice Achet-Aton's Vizier. If you do, create a 4/4 black Demon creature token with flying.

Flash
Flying, first strike, lifelink

Whenever Anima Interrogator attacks, defending player reveals a card at random from their hand.

When Archivist Heretic enters, you lose 1 life, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Asphodel Gravedealer dies, choose one —
• Put a +1/+1 counter on target creature you control.
• Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

When Baneblade Stalker enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

When Beguiling Witch enters, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)
Whenever another creature dies, each opponent mills X cards, where X is Beguiling Witch's power.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Bitter Wanderer desecrates a permanent, each opponent loses 2 life and you gain 2 life.

Lifelink
Revive {3}{B} ({3}{B}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

{1}{B}, Sacrifice another creature, Discard two cards: Search your library for a card, put that card into your hand, then shuffle.

Deathtouch

Menace
Caer Crann Insurgent gets +2/+0 as long as you've foretold a card or cast a foretold spell this turn.

At the beginning of each end step, you gain X life and each opponent loses X life, where X is the number of times you gained life this turn.
{2}{B}: Darksand Acolyte gains indestructible and lifelink until end of turn.

When Fatethief dies, put the bottom card of your library into your hand.
Revive {2}{B}{B} ({2}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever a creature an opponent controls dies, monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)

Menace
Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Gilded Sell-Sword gets +2/+0 as long as you're in a renaissance.

Deception {2}{B} ({2}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Grinning Torturer deals combat damage to a player, torment that player. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Discard a card: Ha'Eng gains deathtouch until end of turn.
Inspired — Whenever Ha'Eng becomes untapped, look at the top card of your library and exile it face down. Then you may pay 3 life. If you do, put all cards you own exiled with Ha'Eng into your hand.

Death knell — Return an Aura card with mana value 5 or less from your graveyard to the battlefield. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
As long as Inconspicuous Otter is enchanted or equipped, he's a 3/4 legendary Otter Rogue named Agent O and has menace.