msem-instigator

Whenever a nontoken creature with mana value 3 or less you control enters, exile it. If you do, create a token that's a copy of it, except it's a Construct creature instead of its other types.

Whenever a Plains you control enters, create a 1/1 white Soldier creature token.
Whenever you attack, you may search your library for a Plains card, reveal it, put it into your hand, then shuffle.

Flying, lifelink
When Helar's Herald dies, target opponent may give themselves two poison counters. If they do, return Helar's Herald to its owner's hand. Otherwise, return Helar's Herald to the battlefield tapped under its owner's control.

Enchant creature
You control enchanted creature.
At the beginning of your upkeep, enchanted creature's owner may have you draw three cards. If they do, sacrifice Take For Ransom.

Untrekked Territory enters tapped.
{T}: Add {B} or {G}.
When Untrekked Territory enters, you may put a loyalty counter on a planeswalker you control.

This spell costs {1} less to cast for each artifact and/or enchantment you control.

Flying
Legendary spells you cast cost {1} less to cast.
{W}{U}{B}{R}{G}: Search your library or graveyard for a legendary card, reveal that card, and put it into your hand. If you searched your library this way, shuffle.

Double strike
Art of war — At the beginning of your end step, if Jaakuna Tyrant dealt damage to an opponent this turn, put a +1/+1 counter on it.

{U}: Primordial Manifestation gets +1/-1 until end of turn.
Whenever Primordial Manifestation deals combat damage to a player, draw a card.

Prevent all combat damage that would be dealt this turn.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Creatures you control with flying get +1/+1.
Whenever a creature you control with flying deals combat damage to a player, you may pay {U}. If you do, draw a card.

Foretell {3}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Draw a card. If this spell was foretold, draw three cards instead.

{U}: Pilgrim's Muse can't be blocked this turn.
{1}{U}: Return Pilgrim's Muse to its owner's hand.
{2}{U}: Scry 2.
{3}{U}: Draw a card.

Flash
When Daughter of Tempests enters, target creature an opponent controls gets -2/-0 until end of turn.
Attain {3}{U} ({3}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Enchant creature
Enchanted creature gets -3/-3.

{T}: Add {C}. Put your choice of a flying, first strike, menace, trample, vigilance, or +1/+1 counter on Planar Rift.
{1}, {T}: Remove any number of counters from Planar Rift: Add {C} for each counter removed this way.
{T}: Move a counter from Planar Rift onto target creature you control. Activate only as a sorcery.

({T}: Add {U} or {B}.)
Muggy Mire enters tapped unless you control two or more basic lands.

Noxious Garden enters tapped.
As Noxious Garden enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Target creature you control gets +3/+3 and gains trample until end of turn. Other creatures you control gain trample until end of turn.

Corsair Sellsword can't block.
Whenever you foretell a card or cast a foretold spell, you may return Corsair Sellsword from your graveyard to your hand.

Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter.)
Blade of the Serpent gets +1/+1 as long as an opponent is poisoned.

Goblin Exploration Team gets +1/+0 for each non-Mountain land you control.

Erratic, erratic, 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. Repeat this process twice.)

{1}{R}: Exile the top card of your library. If it's a creature card, you may play it until the end of your next turn.
{4}{W}: Put two +1/+1 counters on target creature.

Haste
Battalion — Whenever Fellor Tactician and at least two other creatures attack, creatures you control get +1/+1 until end of turn.