msem-instigator

As long as an opponent has one or fewer cards in hand, Valdez gets +2/+0 and has menace.

Choose highest or lowest. Target opponent reveals their hand and discards a card with the chosen kind of mana value among the revealed nonland cards.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
You may play lands from the archived library.

Create an X/X green and blue Plant creature token, where X is the number of differently named lands you control.

Codex — Eleventh Hour Breakthrough; Mentorb; Ostracizer Orb; Possibility Engine; Sealed Riftway; Self Replication. (As this enters, conjure its contents into a shuffled face-up additional library.)
{T}, Sacrifice an artifact: Draw a card from the codex's library.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
{T}: Add {C}.
{1}, {T}: Scry 1.

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}

Each player mills three cards.
Draw a card.

Choose one —
• Exile target player's graveyard.
• Target player sacrifices a creature.

Prowess

Exile target instant or sorcery card from your graveyard. Copy it. You may cast the copy. (Cast a copy of this spell once while this creature is on the battlefield.)

Each player puts the bottom five cards of their library into their graveyard.
Fuse (You may cast one or both halves of this card from your hand.)

Each player sacrifices a creature and discards a card.
Fuse (You may cast one or both halves of this card from your hand.)

Each player sacrifices a creature.

Choose one —
• Destroy target artifact.
• Add {R}{R}{R}.

This turn, players can't search libraries, bring cards from outside the game into game zones, or move cards that began the game face down in the command zone out of the command zone. (An unlocked puzzlebox cannot be unlocked again.)
Draw a card.

Counter target noncreature spell. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Shuffle your hand and graveyard into your library, then draw seven cards. You may have your life total become 10. You may cast a spell from your hand without paying its mana cost. Exile Bright Future.

Flash
When Cane Dancer enters, you may cast target blue instant or sorcery card with mana value 2 from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Each player sacrifices a creature. If a player lost 3 or more life this turn, each opponent sacrifices a creature instead.

Target opponent reveals their hand. You choose a nonland card from it. If you can't, they discard a card. Otherwise, that player discards a card, then if they didn't discard the chosen card, you create a tapped Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Profane Emissary gets +2/+2 and has lifelink as long as you control a Demon.
If you would draw a card, you may instead search your library for a Demon card, reveal it, put it into your hand, then shuffle. You lose life equal to that card's mana value.

Profane Emissary gets +2/+2 and has lifelink as long as you control a Demon.
If you would draw a card, you may instead search your library for a Demon card, reveal it, put it into your hand, then shuffle. You lose life equal to that card's mana value.

As long as an opponent has one or fewer cards in hand, Valdez gets +2/+0 and has menace.

Choose highest or lowest. Target opponent reveals their hand and discards a card with the chosen kind of mana value among the revealed nonland cards.