msem-instigator

Target player reveals two cards at random from their hand. You choose one of them. That player discards that card.

{T}: Target creature gains haste until end of turn.
{1}{R}, {T}, Sacrifice a Human: Create a token that's a copy of the sacrificed creature, except it's a 3/2 colorless Horror. It gains haste until end of turn. Activate only as a sorcery.

Target creature gets -2/-2 until end of turn.
{3}{B}, Exile Rift Splicing from your graveyard: Aetherize target creature card with mana value 3 or less in a graveyard. Activate only as a sorcery. (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever you cast an instant or sorcery spell, reveal the top card of your library. If an instant or sorcery card is revealed this way, draw a card.

Enchant creature
When Aura of Leadership enters, create four 1/1 white Human Soldier creature tokens.
Enchanted creature gets +2/+2.

Flash
Prowess
When High Rollers Esteemed enters, you may choose new targets for target spell or ability unless its controller has High Rollers Esteemed deal 4 damage to them.

Enchant land
Whenever enchanted land becomes tapped, scry 1.
Enchanted land has “{G}, {T}: Each player reveals the top card of their library. Each player that revealed a land card this way may put that card into their hand.”

Enchant creature
Enchanted creature gets +1/+1 and has lifelink.
Sacrifice enchanted creature: Target creature gains lifelink until end of turn. Regenerate that creature. (The next time this permanent would be destroyed this turn, it isn't. Instead tap it.)

Concord — You may cast this spell as though it had flash if there are four or more card types among permanents you control.
When Krill-Clan Guardian enters, it fights up to one other target creature. If that creature would die this turn, return it to its owner's hand instead.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Dawn Over Nizev enters, draw three cards.
When Dawn Over Nizev is defeated, exile it. If you do, you may cast a spell from your hand without paying its mana cost.

Equipped creature gets +3/+0 and has vigilance.
Equip {3}

When Umbersteed dies, target creature an opponent controls gets -4/-4 until end of turn.
Foreshadow {5}{B}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Reach
When Falkenrath Fletcher enters, if an opponent lost life this turn, create a 1/1 black and red Vampire creature token with menace.

First strike

Augmented — When you cast If Memory Serves, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy it twice. You may choose new targets for the copies.
Return target permanent card with mana value 3 or less from your graveyard to the battlefield. Exile If Memory Serves.

Equipped creature has “Whenever this creature attacks or blocks, choose a creature card in your graveyard. This creature gets +X/+Y until end of turn, where X is that card's power and Y is its toughness.”
Equip {2}

Flying, vigilance
Augmented — When Antigravity Agent enters, if you've spent {W}{U}{R}{B}{G} to cast spells this turn, distribute a flying counter and a vigilance counter among one or two creatures you control.

Ravenous Hollow enters tapped.
{T}: Add {B} or {R}.
{2}{B}{R}: Until end of turn, Ravenous Hollow becomes a Wolf creature with first strike in addition to its other types.
Scavenge {2}{B}{R}

{T}, Sacrifice Daunting Skyline: Search your library for a Plains or Swamp card and put it onto the battlefield tapped, then shuffle.

Enchant creature
Converge — When Big Enough enters, put X +1/+1 counters on enchanted creature, where X is number of colors of mana spent to cast Big Enough.
Enchanted creature has trample.

Draw two cards, then discard two cards. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Rapport — Whenever Grayce Blaen and at least one other creature you control become tapped, scry 1, then reveal the top card of your library. If it's a land card, you may put it onto the battlefield tapped.

Target creature gains hexproof and indestructible until end of turn. If it's legendary, put a +1/+1 counter on it.

When Mass Orator enters, if it isn't a token, populate. (Create a token that's a copy of a creature token you control.)
Creature tokens you control get +1/+1.

Equipped creature gets +1/+1.
Equip {1}