msem-instigator

Ward {2}
When Ancient of Lotus Lake enters, draw a card.

You may pay {B} and 4 life rather than pay this spell's mana cost.
Target creature gets -5/-5 until end of turn.

Target player sacrifices a creature. You gain life equal to that creature's toughness.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

First strike
Whenever Sighted-Caste Knight deals combat damage to a player, draw a card.

Target player sacrifices a creature or planeswalker.
Flashback {4}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Return target instant or sorcery card from your graveyard to your hand. Then if this spell wasn't foretold, discard a card.
Exile Spark of Inspiration.
Foretell {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.)

Enchant player
At the beginning of enchanted player's upkeep, if they control two or more creatures and/or planeswalkers, they sacrifice a creature or planeswalker.

When Giku Weaponsmith enters, create two colorless Equipment artifact tokens with “Equipped creature gets +1/+1” and equip {1}.

Counter target artifact or sorcery spell.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{R}{R}: If an instant or sorcery source you control would deal damage to a permanent or player this turn, it deals that much damage plus 2 instead.

Target creature gets +1/+5 until end of turn.
Draw a card.

Equipped creature gets +2/+1.
When equipped creature deals combat damage to an opponent, you may sacrifice Cursebreaker Hammer. If you do, destroy target artifact or enchantment that player controls.
Equip {2}

Equipped creature gets +2/+2 and protection from black and from red.
Whenever equipped creature deals combat damage to a player, that player loses 3 life unless they discard a card or sacrifice a nonland permanent. You discard a card, then you draw two cards.
Equip {2}

Enchant creature
Enchanted creature gets +1/+1 and has hexproof.

When Dark Apprentice enters, mill three cards, then return a creature card from your graveyard to your hand.

{2}{G}, Sacrifice Derrivan Beast Tracker: Create a 3/3 green Beast creature token.

{7}{R}: Up to three target creatures you control get +3/+0 and gain menace until end of turn. This ability costs {2} less to activate if you control a legendary creature.

({T}: Add {W} or {U}.)
Tranquil Stream enters tapped.

At the beginning of each main phase, each player adds {W}{U}{B}{R}{G}.

{T}, Sacrifice another creature: Return target creature card with mana value equal to 1 plus the sacrificed creature's mana value from your graveyard to the battlefield. Activate only as a sorcery.

Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Scribe of the Sky Scrolls. If you spent four or more mana to cast that spell, Scribe of the Sky Scrolls gains flying until end of turn.

If an opponent would draw one or more cards except for the first one they draw in each of their draw steps, instead they draw those cards, then may pay {1}. If they don't pay, they get a poison counter and you draw a card

At the beginning of combat on your turn, you may have target artifact you control become a 3/3 artifact creature until end of turn. If you do, it and Field Engineer attack this turn if able.

Defender
Whenever a land you control enters, you may exile target permanent card from your graveyard.
Sacrifice a land: Put a card exiled with Corpsebark into its owner's hand.