msem-instigator

Haste
Whenever Spotted Slugger deals combat damage to a player, you may have it deal damage equal to its power to target creature.

Trample (This creature can deal excess combat damage to defending player or planeswalker while attacking.)
Sprareos Yearling gets +4/+4 as long as you control five or more lands.

{T}: Add one mana of any color. When this mana is spent to cast an enchantment spell with mana value 5 or greater, draw a card.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Defender
Prismatic — Whenever you cast a multicolored spell, Squall Serpent gets +1/+1 until end of turn and can attack this turn as though it didn't have defender.

Lifelink
{2}{W}: Target Elk gains indestructible until end of turn.

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

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

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

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

Trample, ward {1}
Whenever Stardust Surveyor deals combat damage to a player, you may mill cards until you mill a creature card. When you do, return target creature card from your graveyard to your hand.

{G}, Discard a card: Staunch Constrictor gets +1/+1 until end of turn.

Steel Hunter can't attack unless you control three or more other artifacts.

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.

When Steward of Empire's Cradle enters, you may search your library for a Discovery, Quest, or Saga card, reveal it, then shuffle and put that card on top.
Civilized — If an ability of an enchantment you control triggers, if you control an artifact, a creature and an enchantment, that ability triggers an additional time.

{1}, {T}: Tap target creature with the greatest power among creatures your opponents control.

Still-Smoke Hunter gets +2/+1 and is a Beast in addition to its other types while it's tapped.
Revive {3}{B} ({3}{B}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

{2}{G}: Look at the top three cards of your library. You may reveal a creature or Revelation card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Still-Smoke Sojourners enters, remove all counters from target player or permanent. That player or that permanent's controller loses life equal to the number of counters removed this way.

If you would draw a card, you may skip that draw. If you do, create a tapped Treasure token and exile the top card of your library. You may play that card this turn.

Deathtouch
Menagerie — When Sting-Hopper enters, if there are five or more creature types among creatures you control, target player reveals their hand. You choose a creature card from it. That player discards that card.

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.