msem-instigator

{2}{B/G}: Return Silthway Scuttler from your graveyard to your hand.
{2}{B/G}, Exile Silthway Scuttler from your graveyard: Put two +1/+1 counters on target creature.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Siltsplitter desecrates a permanent, each opponent sacrifices an artifact.

When Silverhorn Tactician enters, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Trample
Whenever Simian Sentinel attacks, it gets +X/+0 until end of turn, where X is the number of lore counters on Sagas you control.

First strike

Whenever Simian Striker attacks, it gets +3/+0 until end of turn.

Target player sacrifices a creature.
Fabled {2}{B} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Equipped creature gets +1/+0 and has menace.
Equip {2}

Counter target spell.
Forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Mill a card. Target creature gets -X/-X until end of turn, where X is the number of cards put into your graveyard from anywhere this turn.

Return up to one target creature card from your graveyard to your hand, then exile all graveyards.

This spell costs {1} less to cast for each poison counter your opponents have.
Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)
At the beginning of your end step, each opponent with seven or more poison counters loses the game.

Counter target spell. If you control a Wizard, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Draw a card, then forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Whenever Sirif of the Lord's Legion attacks, you may put a lore counter on target Saga you control.
Whenever Sirif deals combat damage to a player, you may remove a lore counter from target Saga you control.

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.)

{T}, Sacrifice Skeletal Oasis: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

When Skeletal Shredwing enters, target creature can't block this turn.
Revive {5}{R} ({5}{R}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

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.

Whenever an embattled creature you control dies, you may return Skhorvall Eternal from your graveyard to your hand. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Flying
Whenever Skhorvall Patrol deals combat damage to a player, look at the top card of that player's library.

When Skhorvall Raider enters, if you control an embattled creature, Skhorvall Raider deals 2 damage to any target. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Menace
Whenever Skhorvall Warleader attacks, it gets +1/+0 until end of turn for each other attacking Warrior you control.

Skin from Bone deals damage to target creature equal to your fealty to Mountains. (Each Mountain you control counts towards your fealty to Mountains.)