msem-instigator

Target creature gains haste until end of turn. That creature attacks or blocks this turn if able.

Exile target artifact an opponent controls. Until end of turn, you may cast a copy of that card. (You still pay its costs.)

Flying
Whenever you foretell a card or cast a foretold spell, you may scry 1.

Counter target artifact or sorcery spell.

Whenever a creature enters the battlefield 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 the battlefield, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

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.

Whenever you draw a card, put a dream counter on Stargazing.
Remove seven dream counters from Stargazing and exile it: Shuffle your hand and graveyard into your library, then draw seven cards.

Until end of turn, if a source you don't control would deal damage to you or cause you to lose life, mill that many cards instead.

Steelborn Apprentice gets +1/+1 as long as you control an Equipment.

Flash
Advance {3}{W} (Cast this for {3}{W} to advance it as it enters. {3}{W}: Advance this as a sorcery.)
Whenever Steelwoven Soldier advances, it gets +2/+2 until end of turn.

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Create a tapped token that's a copy of target token you control.

Enchant creature
When Sting of the Manticore enters the battlefield, scry 2.
Enchanted creature gets +1/+0 and has deathtouch.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever you cast a spell that doesn't share a color with Stinging Hunter, each opponent loses 1 life.

Choose a nonland card type. Target player reveals their hand. You choose a card of the chosen type from it. That player discards that card.

Creature spells cost {1} more to cast.
At the beginning of your upkeep, put a decay counter on Stonewood Sanctuary. Then if it has three or more decay counters on it, sacrifice it.

Colossal 3—{4}{R} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {4}{R} as a sorcery: Put three +1/+1 counters on it if it has none.)
When Storm-Eye Salamander's colossal ability puts one or more counters on it, exile the top three cards of your library. Until the end of your next turn, you may play one of those cards.

Prowess, haste

Whenever one or more creatures you control deal combat damage to a player, exile a nonland card from that player's graveyard. Copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter the battlefield as tokens.)

{1}, {T}: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
{2}, {T}, Exile an instant or sorcery card from your graveyard: Stormvolt Apprentice deals 1 damage to each opponent.

At the beginning of your upkeep, mill two cards.
{1}{G}, Sacrifice Strange Discovery: Return target card from your graveyard to your hand.

Street Busker gets +2/+0 as long as you've gained life this turn.

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked by creatures with greater mana values.

When Street Stalker enters the battlefield, target opponent loses 1 life for each creature you control named Street Stalker.