msem-instigator

Skysworn Aspirant has flying as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flying
Whenever an embattled creature you control deals combat damage to a player, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Whenever Skysworn Savior attacks, you may return another creature you control to its owner's hand. If you do, Skysworn Savior gets +2/+2 and gains flying until end of turn.

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.

Put a +1/+1 counter on up to one target creature you control. That creature can't be blocked this turn.
Draw a card.

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

(Transform this if it's not attached to a creature. Pay {2}{W} as a sorcery to unattach it.)
Enchant creature you control
Slopestrider's Chariot's rider gets +1/+1 and has double strike.

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.

Equipped creature gets +2/+1.
Whenever equipped creature blocks or becomes blocked by a creature, it deals 2 damage to that creature.
Equip {2}

When Smuggler of the Santriza enters, you may discard a card. If you do, draw a card.

Equipped creature gets +1/+1.
Whenever equipped creature attacks, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Equip {2}

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.

When Sofia's Swashbucklers enters, you may return target card with foretell from your graveyard to your hand.

Foretell {B}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Haste
Whenever Sofia deals combat damage to an opponent, exile the top card of that player's library face down and look at it. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell. Then foretell Sofia. It costs {0} to foretell this way.

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.

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

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

{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.

All creatures get -2/-2 until end of turn. At the beginning of the next end step, if three or more creatures died this turn, create two tapped Treasure tokens.

Whenever a land you control enters, you gain 1 life.
{3}{G}, Sacrifice Sower of Spring: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Sparring Ground enters with a +1/+1 counter on it.
{T}: Add {C}.
Whenever a creature you control enters, you may move a +1/+1 counter from Sparring Ground onto that creature.

Enchant creature
When Spectral Chains enters, create two 1/1 white Spirit creature tokens with flying.
As long as you control a creature, enchanted creature can't attack or block and its activated abilities can't be activated.