msem-instigator

When Sire of the Wild enters, reveal the top four cards of your library. You may put a creature card from among them onto the battlefield. Shuffle the rest into your library.

Trample
Skalnir, Ruinbringer enters with X +1/+1 counters on it.
When Skalnir, Ruinbringer enters, it deals damage equal to the number of +1/+1 counters on it to each creature without trample.

Skavi Behemoth can't be the target of nongreen spells or abilities from nongreen sources.

Whenever Skeigr, Skhorvall Flagship attacks, it deals 3 damage divided as you choose among one, two, or three targets.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Resolute — Skerry Serpent must be blocked if able as long as its power is greater than its base power.

Menace
Whenever an opponent casts a spell, Skhorvall Behemoth gets -2/-2 until end of turn.

Reach

This spell can't be countered.
{U}: Exile Skulkling. Return it to the battlefield under its owner's control at the beginning of the next end step.
{1}{U}: Until end of turn, Skulkling gets +1/-1 and can't be blocked.
{3}{U}: Draw a card. Create a 1/1 blue Rogue creature token.

Flying, trample, haste
Whenever a land you control enters or a land is put into your graveyard from the battlefield, Skyscreecher Dragon deals 2 damage to each opponent.

Trample

Deathtouch
When Slum Scrounger enters, put up to two target creature cards in your graveyard on top of your library in any order.

When Snagged Truck enters, investigate three times. (Create three colorless Clue artifact tokens with “{2}, Sacrifice this: Draw a card.”)
Snagged Truck can't attack or block as long as you control a Clue.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Flash
Wither (This deals damage to creatures in the form of -1/-1 counters.)

If you control seven or more creatures, you may cast Sociable Giant without paying its mana cost.
Trample

Solar Hatching deals 4 damage to each creature.
Coalesce {6}{R}{R} (You may cast this from your graveyard for {6}{R}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
When Solar Hatching enters, each player chooses up to two lands they control and sacrifices the rest.

Whenever Solemn Stag perseveres, put two +1/+1 counters on it. (A creature perseveres when it survives damage.)

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Whenever a creature you control attacks alone, untap all lands you control.

Defender, reach
When Soothevine Elemental enters, draw a card.

Reach
{3}, Exile Sorrowful Seeker from your hand: Draw a card. You may cast this card for as long as it remains exiled.

Flying, trample, haste
{W}{U}{B}{R}{G}: Create a token that's a copy of another target creature except it's all colors and has haste.
{W}{U}{B}{R}{G}, Exile Soul of Iscathia from your graveyard: Create a token that's a copy of target creature except it's all colors and has haste.

Protection from colored spells
{5}{C}{C}: Exile target colored permanent.
{5}{C}{C}, Exile Soul of Muetar from your graveyard: Exile target colored permanent.

Trample
Whenever a creature dealt damage by Sovereign of Old Lovi this turn dies, put a +1/+1 counter on Sovereign of Old Lovi.

Whenever Sower of Sabne's Harvest enters or attacks, align X, where X is your fealty to Forests. (Choose modes with total ★ less than or equal to the number of Forests you control. You may choose modes multiple times.)
• ★★ — Put a +1/+1 counter on target creature.
• ★★★ — Exile target artifact or enchantment.
• ★★★★★ — You gain 5 life.

Whenever Sower of Virulent Thoughts attacks, you may return a creature you control to its owner's hand. If you do, put a +1/+1 counter on target creature you control.

Creatures your opponents control can't block alone. (They can block different creatures.)