msem-instigator

Whenever Sirif of the Lord's Legion attacks, you may put a lore counter on target Saga you control.
Whenever Sirif deals combat damage to a player, you may remove a lore counter from target Saga you control.

Whenever you activate a nonmana ability of a permanent during your turn, you may choose one that hasn't been chosen yet this turn —
• That permanent becomes a 3/3 Dragon creature with flying in addition to its other types until end of turn.
• Each opponent discards a card and loses 2 life.
• Copy that ability. You may choose new targets for the copy.

Double strike
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever Sisters Suzakazi attacks, if you control another creature named Sisters Suzakazi, it deals 3 damage to any target.

Prowess
Whenever Siv Katari, Rebel Technician attacks, create a tapped and attacking X/X colorless Construct artifact creature token with prowess, where X is Siv Katari's power. Exile that token at end of combat.

Flying, trample
Whenever Skali, the Last Sunfeather attacks, abound. If a creature spell is cast this way, you may have that creature enter tapped and attacking. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

Trample
Skalnir, Ruinbringer enters with X +1/+1 counters on it.
When Skalnir, Ruinbringer enters, it deals damage equal to the number of +1/+1 counters on it to each creature without trample.

Whenever Skeigr, Skhorvall Flagship attacks, it deals 3 damage divided as you choose among one, two, or three targets.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Whenever an opponent is dealt damage by one or more sources you control for the second time each turn, draw a card.

{T}, Discard your hand: If two or more cards were discarded this way, search your library for a card and put that card into your hand, then shuffle.

Trample, haste
Skullbriar gets +1/+1 for each creature card in all graveyards.
{T}: Add {B} or {G}.
Skullbriar, Death's Mockery remains transformed as it moves to any zone other than a player's hand or library.

Flash
Flying
Whenever you cast a spell during an opponent's turn, create a Weapon token. When you do, you may attach it to another target creature with flying. (It's an Equipment artifact token with equip {2} and “Equipped creature gets +1/+1”.)

Creatures can't attack you unless their controller pays {2} for each of those creatures.
Whenever a permanent is returned to a player's hand, create a 1/1 white and blue Bird creature token with flying.

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When Skypath Pilgrimage enters, journey twice. (Exile the top two cards of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

Enchant creature
Enchanted creature gets +1/+1.
Whenever enchanted creature deals damage to a player or planeswalker, draw a card.

Whenever Slaffield Workgate or another enchantment you control enters, create a 0/2 white Ox creature token.
{3}{W}: Return another target enchantment you control to its owner's hand.

Improve {1}{B/R} ({1}{B/R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Enchant land
Whenever enchanted land is tapped for mana, its controller adds {G}.
{G}, Sacrifice Sleeping Dryads: Draw a card.

Enchant opponent
Whenever you attack enchanted player, look at the top X cards of your library, where X is one plus the number of attacking creatures you control. Put one of those cards into your hand and the rest on the bottom of your library in any order.

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

(Add a quest counter as this enters. Sacrifice after 3.)
Once each turn, when you cast an instant or sorcery spell, you may add a quest counter.
1, 2 — Slipsand Expedition deals damage equal to the number of quest counters on it to any target.
3 — Add {R}{R}{R}.

(Transform this if it's not attached to a creature. Pay {2}{W} as a sorcery to unattach it.)
Enchant creature you control
Slopestrider's Chariot's rider gets +1/+1 and has double strike.

When Smirk enters, add the top two cards of your library to your evil plan. (Look at them, then exile them face-down. You may pay {7} once a turn as a sorcery to cast any number of cards in your evil plan without paying their mana costs.)
Whenever you cast your second spell each turn, you draw a card and you lose 2 life.

Enchant creature
Enchanted creature has poisonous 3. (Whenever that creature deals combat damage to a player, that player gets three poison counters.)

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.
Whenever you make first contact, scry 1. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)