msem-instigator

Lifelink
Players casting spells and creatures entering don't cause abilities to trigger.

Rosesworn Knight gets +1/+1 as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Whenever you cast a noncreature spell, Slyten Technician gets +1/+0 until end of turn, then scry 1.

Whenever a permanent you control leaves the battlefield, if it had counters on it, you may put those counters on Stage Magician.
At the beginning of your end step, you may move any number of counters from Stage Magician onto target permanent you control.

Riga's Workshop enters tapped.
When Riga's Workshop enters, you may mill two cards.
{T}: Add {U} or {R}.

Damage dealt by Deepwater Stinger can't be prevented.

First strike
Back-Alley Gnoll has lifelink as long as it's enchanted by a black Aura.
Back-Alley Gnoll gets +2/+0 as long as it's enchanted by a red Aura.

When Dualglaive Acolyte enters, create a green Aura enchantment token named Calamighty attached to target creature. The token has enchant creature and “Enchanted creature gets +1/+1 and can't be blocked by creatures with power 2 or less.”

Put X -1/-1 counters on up to one target creature. Exile up to one target card from a graveyard.

Whenever one or more creatures you control deal combat damage to a player, that player discards a card. Then that player may discard another card. If they don't, create two 2/1 black Nightmare creature tokens with “This creature can't block.”
Fleeting {1}{B}{B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

({T}: Add {G}, {W}, or {U}.)
Stalwart Dominion enters tapped.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
When Sower of Wishes enters, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest back on top in any order.

If an effect would cause an opponent to discard one or more cards while they have fewer than that many cards in hand, they lose life equal to three times the difference instead of discarding the excess cards.

Once during each of your turns, when you cast an instant or sorcery spell, you may create a Function token with that spell's effects. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell. A spell's effects includes added functions.)

Whenever you cycle a card, reveal the top two cards of your library. You may put a permanent card from among them into your hand. Put the rest on top of your library in any order or into your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Crinster Blacksmith enters, nourish 2. (To nourish 2, either put two +1/+1 counters on this creature or create two 1/1 white Citizen creature tokens.)

Expunge the Terrors deals X damage to target creature or planeswalker.
Madness—{1}{R}, Exile X cards from your graveyard. (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Flash
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{1}: Remove target attacking creature you control from combat and untap it.

When Mana Potion enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Mana Potion: Add two mana of any one color.

Clocktower Hideout enters tapped.
When Clocktower Hideout enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {B} or {R}.

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 1 life.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Counter target creature spell. You may cast a copy of that spell. (You still pay its costs. The copy becomes a token.)

Choose one —
• You draw two cards and you lose 2 life.
• Target player discards two cards and you gain 2 life.

Deathtouch
Inspired — Whenever Yenzu Nightblade becomes untapped, target creature you control gets +1/+1 and gains deathtouch until end of turn.