msem-instigator

Equipped creature gets +1/+1.
At the beginning of combat on your turn, choose flying, first strike, vigilance, trample, or haste. Equipped creature gains that ability until end of turn.
Equip {2}

{1}, {T}: Untap target creature.

Enchant creature or enchantment
Enchanted permanent doesn't untap during its controller's untap step.
Enchanted permanent can't have counters put on it.

Destroy target attacking creature with mana value 3 or less.

As Stained Reliquary enters, choose a card type.
{T}: Target player exiles a card from their graveyard of the chosen type.
{2}, Exile Stained Reliquary: Exile all graveyards. Create a tapped 1/1 white Spirit creature token with flying.

Put a +1/+1 counter on target creature. (Then exile this card. You may cast the creature later from exile.)

You draw X cards and you lose X life, where X is the number of cards in your hand.

Whenever a creature enters under your team's control, reveal the top card of your library. If it's a creature card, you gain 2 life.

Lifelink
When Stalked Healer enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flash
When Stalker in the Mist enters, up to one target creature gets -1/-0 until end of turn.

Bloodprice {2}{U} (You may cast this card by sacrificing a creature and paying its bloodprice.)

Menace
Stalker of Myth gets +1/+0 for each creature you control with chronicle.
{2}, Remove a counter from a permanent you control: Draw a card, then discard a card.

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Vigilance, trample
At the beginning of combat on your turn, put a +1/+1 counter on target legendary creature you control.

({T}: Add {G}, {W}, or {U}.)
Stalwart Dominion enters tapped.

Stalwart Guardian has first strike as long as it's attacking.
Augmented — When Stalwart Guardian enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, create two 1/1 blue Elemental creature tokens with flying.

When Stalwart Physicker enters, you may remove a -1/-1 counter from target creature.

Flying, first strike, lifelink
When Stalwart Seraph enters, untap all creatures you control.

Flash (You may cast this spell any time you could cast an instant.)
When Stampede Instigator enters, target creature gets +2/+3 until end of turn.

Trample
Other creatures you control with trample get +2/+2.
{4}{R}{G}: Put a trample counter on target creature.

This spell costs {1} less to cast if it targets an embattled creature. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Put two +1/+1 counters on target creature you control and untap it. It gains hexproof and trample until end of turn.

Target creature you control gets +0/+6 until end of turn and can block an additional creature this turn. Untap it.

You gain 7 life.
Coalesce {5}{G}{G} (You may cast this from your graveyard for {5}{G}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Target creature you control gains indestructible until end of turn. If that creature is a Scout, you gain 1 life for each land you control.

Until end of turn, creatures and artifacts you control gain “{T}: Tap target permanent.”