msem-instigator

Whenever you discard an instant or sorcery card, you may cast it from your graveyard. (You still pay its costs.)
Spells you cast from anywhere other than your hand cost {1} less to cast.

Haste
When Speaker of the Iris enters, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
Other creatures you control have haste.

Reach
Whenever this creature attacks, target creature with power less than or equal to the number of creatures you control can't block this turn.
{3}{G}: Attacking creatures get +1/+0 and gain trample until end of turn.

Swiftstep Cliffdweller has haste as long as you control another Goblin.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{6}{R}: Takara Flameblade deals 4 damage to target creature. Activate only once each turn.

When Tomb-Raider Duo enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Haste
Whenever Tortle Waymaker becomes blocked, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
When Treacherous Devil enters, if an opponent passed the trial, that player gains control of Treacherous Devil.

Flying
Whenever you cast your first noncreature spell each turn, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

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

Menace
Whenever a player gains life, that player sacrifices a permanent.

Haste
{2}{U}: Volatile Alchemist gains vigilance until end of turn and can't be blocked this turn.

Haste
When Wretched Merfolk enters, target creature can't block this turn.

When Yamisaran Bladedancer enters, you may attach an Equipment you control to target creature you control.

Young Dragonheart gets +1/+0 and has first strike as long as you control a legendary creature.

Other Rebel creatures you control get +1/+0.
When Youthful Renegade enters, create a 1/1 white Rebel creature token.

Whenever Zana, the Dreamer attacks, you may pay {3}{R}{R}. If you do, for each attacking nontoken creature you control, create a tapped and attacking token that's a copy of it, except the tokens aren't legendary. Exile those tokens at the beginning of the end step.

Whenever two or more creatures an opponent controls block, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Enchanted creatures you control have menace.

Whenever Zealous Scaleblight becomes tapped, it deals 1 damage to any target.

{G}: Tap Adaptive Troll. It gains indestructible until end of turn.
At the beginning of each upkeep, if Adaptive Troll was dealt lethal damage last turn, put a counter of your choice on it from among vigilance, deathtouch, reach, trample, and +1/+1.

Deathtouch
Whenever Addermark Eviscerator deals combat damage to a player, draw a card.
At the beginning of your end step, if Addermark Eviscerator didn't attack this turn, transform it.

{T}: Adept Fisherman voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Adept Fisherman phases in, you gain 2 life.

Trample
Wanderlust — Whenever Akkrixian Assailants attacks, if you control four or more differently named lands, put a +1/+1 counter on it.

Alluring Rider must be blocked if able.
Attain {4}{G} ({4}{G}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Trample
As long as it's an opponent's turn, Ambushing Alligator is a blue Bird with base power and toughness 1/1 and has flying and hexproof.