msem-instigator

Flying, lifelink
Sacrifice a creature: Until end of turn, Turned Watcher gets +1/+0 and gains “Whenever Turned Watcher deals combat damage to a player, draw a card.”

{1}{U}: Twilight Privateer voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Twilight Privateer phases in, up to one other target creature voyages.

Each creature you control with a +1/+1 counter on it has double strike.
If one or more +1/+1 counters would be put on a creature you control, put that many plus one +1/+1 counters on that creature instead.

Choose one —
• Scry 3. Draw a card.
• Fateseal 3. That player draws a card. (To fateseal 3, look at the top three cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Other creatures you control have base power and toughness equal to this creature's base power and toughness.

Menace
Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)

Each player sacrifices two creatures, then gains 2 life and draws a card for each creature they sacrificed this way.

Creature tokens you control get +1/+1 and have distorted. (They can be blocked by tapped creatures but not untapped creatures.)

Flash
When Twisted Speaker enters, return target spell to its owner's hand. That spell's controller loses 2 life.

Whenever one or more cards are put into an opponent's graveyard from their hand or library, you may exile the top card of each player's library. Until your next turn, you may cast a card from among those exiled cards and you may spend mana as though it were mana of any type to cast that spell.

Whenever Twitchy Pyromancer enters or attacks, it deals 1 damage to any target. Whenever a creature dealt damage this way dies this turn, upgrade Twitchy Pyromancer. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Menace
• Prowess

Sacrifice a creature: Two-Faced Aristocrat gains indestructible until end of turn.
Attain {4}{B} ({4}{B}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Creatures you control dying cause abilities of that creature to trigger as though that creature entered.
{2}{W}{B}, Sacrifice another creature: Destroy target nonland permanent.

{3}{U}: Tap target creature. Activate only as a sorcery.
Cycling {2/U} ({2/U}, Discard this card: Draw a card.)

When you cast this spell, copy it for each Dragon permanent you control. You may choose new targets for the copies.
Tyrant's Breath deals 7 damage to target creature or planeswalker.

Flash
When Tyrus, Giver to All enters and at the beginning of combat on your turn, for each counter on permanents you control, you may move that counter from that permanent to another permanent you control.

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{5}, {T}, Discard a card: Create a 0/0 colorless Construct artifact creature token with “This creature gets +1/+1 for each artifact you control.” It can't block this turn.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
As Ulek Wayfinder envisions a land card, you may put that card onto the battlefield tapped.

Flying
{1}{R}{R}{R}: Return Umbral Hunter from your graveyard to your hand. If it's the declare attackers step, up to one target attacking creature gets +3/+1 until end of turn.

Target creature gets -5/-0 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Destroy target artifact or enchantment. You gain life equal to its mana value.

Target creature gets +1/+1 and gains double strike until end of turn. (That creature deals both first-strike and regular combat damage.)

Put two -1/-1 counters on target creature.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Creatures your opponents control get -2/-0 until end of turn.
Draw a card.