msem-instigator

When Cave Eel enters, look at the top three cards of your library. Put one on top and the rest on the bottom in any order.

Flash
When Cocky Bladesinger enters, it gains first strike, lifelink, and haste until end of turn.

Harmony — Exile another target creature until Pretentious Performer leaves the battlefield.
When Pretentious Performer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Rain of Blood deals 3 damage to each creature and each player.

Flying
When Ethereal Savior enters, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.

Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a creature you control deals combat damage to a player, put a time counter on Lavacore Elemental.

Changeling (This card is every creature type.)
{1}{G/U}: Vune, the Facemaker becomes a copy of target creature you control, except its name is Vune, the Facemaker, it's legendary, and it has changeling and this ability. Activate only as a sorcery.

Flash
Menagerie — When Tidal Trickster enters, if there are five or more creature types among creatures you control, you may search your library for a card named Tidal Trickster, reveal it, put it into your hand, then shuffle.

Defender, trample
Whenever you lose life, Loyal Watchdog may attack as though it didn't have defender until the beginning of your next end step.

[0]: Choose up to one target creature. You may put two +1/+1 counters on it, a +1/+1 counter on it and a loyalty counter on Aoia, Monarch of Beauty, or two loyalty counters on Aoia.
[–2]: Exile target creature, then return it to the battlefield. For each kind of counter on it before it left, put that many of that kind of counter on it.
[–9]: You get an emblem with “If an effect would put one or more counters on a permanent you control, it puts five times that many of those counters on that permanent instead.”
Aoia can be your commander.

Sacrifice any number of permanents. If five colors were among the sacrificed permanents, each player exiles the top five cards of their library. For each player, you may cast up to two cards they exiled this way without paying their mana costs.

Put target creature card from a graveyard onto the battlefield under your control. If that card was put into that graveyard this turn, it enters with an additional +1/+1 counter on it.

Empress Kogane can't attack or block.
Whenever an opponent casts a spell, you may gain life equal to that spell's mana value.

Sacrifice Amateur Auteur: Destroy target enchantment.

Enchant creature
As Hunter's Distinction enters, you may tap enchanted creature if it's untapped. When you do, put three -1/-1 counters on target creature with flying.
Enchanted creature gets +3/+2 and has reach.

When Sandbluff Confiscator enters, you may tap or untap target artifact or creature.

Target creature gains deathtouch and indestructible until end of turn.

Noncreature spells your opponents cast cost {1} more to cast.

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 Agent of Long Shadows deals combat damage to a player, you may put a Rogue card from your hand or graveyard onto the battlefield.

Whenever you investigate for the first time each turn, investigate an additional time.
{T}, Sacrifice an artifact: Cadalon Inspector deals 2 damage to any target.

Haste
Sacrifice another creature: Bygone Aristocrat gains indestructible until end of turn.

Menace
Whenever Coirchanh deals combat damage to a player, return up to one target creature card with toughness 4 or greater from your graveyard to the battlefield with a finality counter on it.
{1}{G}: This creature gets +0/+2 until end of turn.

Flying
When Cathedral Gargoyle dies, you gain 2 life and create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
Foreshadow {4}{W} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Destroy target nonland permanent.
If you've sacrificed a permanent this turn, draw a card.