msem-instigator

When Slaug's Warhowler enters, create a 1/1 red Goblin creature token with haste.
When Slaug's Warhowler dies, you may discard a card. If you do, draw a card.

Improve {1}{B/R} ({1}{B/R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Target creature blocks this turn if able. You may have it gain reach until end of turn.
Draw a card.

Goad up to one target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Draw a card.

Destroy target artifact. Smoldering Pages deals damage to that artifact's controller equal to that artifact's mana value.

Enchant creature
Enchanted creature has poisonous 3. (Whenever that creature deals combat damage to a player, that player gets three poison counters.)

Target creature gains deathtouch and poisonous 1 until end of turn. (Whenever that creature deals combat damage to a player, that player gets a poison counter.)
Inscribe {1}{G} ({1}{G}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Up to two target creatures can't be blocked this turn. Until end of turn, whenever either of those creatures deals combat damage to a player or planeswalker, you draw a card.

Flying
Whenever Soaring Biome attacks, create a Plains token, Island token, Swamp token, Mountain token, or Forest token. Sacrifice that land at the beginning of the next end step.
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.)

Create a 1/1 blue Bird creature token with flying.
Inscribe {2}{U} ({2}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

({T}: Add {G} or {U}.)
Soaring Rainforest enters tapped.
{1}, {T}: Add {G}{G} or {U}{U}.

Flying, vigilance
Whenever one or more other creatures you control attack, those creatures get +0/+2 until end of turn.
Whenever one or more other creatures you control block, those creatures get +2/+0 until end of turn.

At the beginning of each player's upkeep, that player may pay {2} or 2 life. If they don't, they return a permanent they control to its owner's hand.

Target creature gets -3/-3 until end of turn. If you control a legendary creature, instead destroy that creature.

When Soul Jar enters, exile target creature and each other creature with the same name as that creature until Soul Jar leaves the battlefield.

Destroy target creature unless its controller pays {3}.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of your upkeep, exile up to one target nonland permanent you own. Return that card to your hand. If Soul Reader has two or more counters on it, you may instead return that card to the battlefield under your control.

When Soulblade enters, exile target creature card with mana value 3 or less from your graveyard.
Whenever equipped creature attacks, create a token that's a copy of a card exiled with Soulblade that's tapped and attacking. Exile the token at end of combat.
Equip {1}

{1}, Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.

Poisonous 3 (Whenever this creature deals combat damage to a player, that player gets three poison counters.)
When Soulbreaker of Mautakesh enters, target poisoned player sacrifices a creature.

Activated abilities of cards in your graveyard cost {2} less to activate.

Activated abilities of cards in your hand cost up to {1} less to activate. This effect can't reduce the amount of mana an ability costs to activate to less than one mana.

{1}, Sacrifice Sovereign Stone: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{1}, Sacrifice Sovereign Stone: Draw a card.

Counter target spell unless its controller pays {X}. Look at the top X cards of your library. Put up to one of them on top of your library and the rest on the bottom of your library in a random order.

Flying, haste
Whenever you cast an instant or sorcery spell, Sovereign of Old Jidai gets +1/+0 until end of turn.