msem-instigator

Landfall — Whenever a land you control enters, create a 5/5 green Wurm creature token with trample.

Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)
When Tutorial Boss enters, create a 1/1 blue Pirate creature token.

({T}: Add {G} or {W}.)
As Sunlit Plaza enters, you may pay {1}. If you don't, Sunlit Plaza enters tapped.

Flying, haste
Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Splitflame Phoenix dies, you may pay {R}. If you do, return it to its owner's hand.

Flying
Whenever Searshot Dragon deals combat damage to a player, it deals that much damage to target creature that player controls.
{1}{R}: Searshot Dragon gets +1/+0 until end of turn.

Enchant creature
Enchanted creature has “Whenever this creature deals damage to an opponent, you may draw a card.”

Whenever you cast a creature or planeswalker spell, if mana produced by a nonland permanent was spent to cast it, it gains trample and haste until end of turn.
{T}: Add {R} or {G}.

This spell costs {1} less to cast for each Scarecrow you control.
Other creatures you control get +0/+2 and have vigilance.

When Ethereal Pact enters, each player shuffles their hand and graveyard into their library, then draws seven cards.
Each player can't cast more than one spell each turn.

Search your library for a basic land card and put that card onto the battlefield tapped, then shuffle.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Nightwatch Rallier enters with X +1/+1 counters on it.
Other artifact creatures you control get +1/+1 for each +1/+1 counter on Nightwatch Rallier.

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
When Devilish Undoer enters, if the trial was failed, return target creature card from your graveyard to your hand.

Create a 0/0 green Wurm creature token with “This creature gets +1/+1 for each permanent card in your graveyard.”
If you would draw a card, you may instead sacrifice two lands and mill two cards. If you do, return Ruchong Awakening from your graveyard to your hand.

Deception {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible.
[+1]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.

When Expensive Tutor enters, tap target land. It doesn't untap during its controller's next untap step.

Flying
Herald of Oblivion enters with X -1/-1 counters on it, where X is your life total.

Target creature you control fights target creature you don't control.
Flashback {5}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Equipped creature gets +1/+1. If it's a token, it gets +3/+3 instead.
Equip {2}

At the beginning of your end step, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Whenever you cast a spell, if you sacrificed permanents, discarded cards, and/or paid life as an additional cost to cast it, Kernel Knot deals 2 damage to any target. (Sacrificing permanents for mana doesn't count.)

Flying
When Planchette Poltergeist enters, you may exile target creature. Its owner may cast it from exile for as long as it remains exiled.

When Sundering Arcanist enters, you may destroy target artifact or enchantment.
If you would draw a card, you may sacrifice a land and mill four cards instead. If you do, return Sundering Arcanist from your graveyard to your hand.

When Silver Gardener enters, create a 1/1 green Saproling creature token.
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

Trample
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever a creature an opponent controls blocks, Master of No Quarter deals 2 damage to that creature.

When Cadalon Experimenter enters, if you control an artifact, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)