msem-instigator

Whenever Implant Tinkerer or another artifact you control enters, choose one —
• Put a +1/+1 counter on that artifact.
• Implant Tinkerer deals 1 damage to any target and you gain 1 life.

Codex — Aspiring Dragon; Scrappy Hatchling; Skiviar Scraplord; Blizzard Dragon; Cloud Swine; Gold Retriever; Ilieth, Transcendent. (As this enters, conjure its contents into a shuffled face-up additional library.)
At the beginning of your upkeep, you may put a card from this codex's library on the bottom of that library.

[+1]: Create a tapped 3/3 black Crocodile creature token with menace.
[–1]: You may cast a copy of Size Up.
[–7]: Each land you control becomes a 3/3 Crocodile creature and gains menace and haste until end of turn.

Destroy target nonland permanent with mana value 3 or less. (Then exile this card. You may cast Irbek later from exile.)

Codex — Little Pig; Charging Cassowary; The Lonely Hunter; Shadowlurk; Blood Constrictor. (As this enters, conjure its contents into a shuffled face-up additional library.)
You may cast Adventures of this codex's contents from your graveyard.

Destroy target permanent. Trigger a death knell of any number of permanents you control.

Whenever you make first contact, you may activate one of Karina's loyalty abilities. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)
[+1]: Each player draws a card.
[–2]: Exile target nonland permanent. At the beginning of the next end step, return it to its owner's hand or to the battlefield under its owner's control.
[–7]: You get an emblem with “You may cast spells that don't have the same name as a permanent you control or a card in your graveyard without paying their mana costs.”

Flash
When Leafcrowned Fox enters, return to your hand target creature card from your graveyard that was put there from anywhere this turn. If it has mana value 3 or less, you may return it to the battlefield under your control instead.

First strike, trample
Death knell — Return a permanent card with mana value less than X from your graveyard to the battlefield, where X is the mana value of the last creature that died this turn. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Whenever you make first contact, create a 1/1 white Bird creature token with flying. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)
Whenever three or more creatures you control deal combat damage to a player, create a token that's a copy of another target permanent you control.

Whenever a player discards a card, you may draw a card and put a loyalty counter on Mei Liva, the Broken.
[0]: Target permanent's controller sacrifices it unless they discard two cards.
[–1]: Each opponent loses X life and you gain X life, where X is the number of cards in your hand.
[–3]: Target player chooses a card in their hand, then discards the rest.

Codex — Out-of-Body Experience; Event Horizon; Strike from the Shadows; Second Death; Anguished Unmaking. (As this enters, conjure its contents into a shuffled face-up additional library.)
You can't draw from this codex's library.
Whenever a creature you control dies, put a card from this codex's library into your hand.

When Paint by Numbers enters, put up to ten brush counters on it.
Whenever a player casts a instant or sorcery spell with mana value equal to the number of brush counters on Paint by Numbers, remove a brush counter from it and copy that spell. You may choose new targets for the copy. Then sacrifice Paint by Numbers if it has no brush counters.

Creatures you control with +1/+1 counters on them have haste and trample.
At the beginning of combat on your turn, target creature explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card into your graveyard.)

[+1]: Artifact creatures you control get +1/+1 and gain haste until end of turn.
[–X]: You may cast an artifact card with mana value X or less from your hand without paying its mana cost. If it has {X} in its cost, {X} is X.
[–6]: Choose a number. For each artifact you control with the mana value equal to the chosen number, create a token that's a copy of it.

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.

At the beginning of combat on your turn, target creature you control explores three times. It attacks this combat if able and other creatures you control can't attack this combat. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Death knell — You may sacrifice a nontoken creature. If you do, create a 3/3 black Spirit creature token. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Creatures you control dying causes their death knell to trigger. (In addition to the normal death knell trigger.)

Lifelink, haste
Equip abilities that target Rose of Sunspear cost {X} less to activate, where X is her power.

{2}, Remove a +1/+1 counter from a creature you control: Draw a card.

Whenever a creature enters without counters during your next turn, you may put two +1/+1 counters on it. (Then exile this card. You may cast the creature later from exile.)

When Snarling Devil enters, create four 1/1 black Possum Dog creature tokens.
At the beginning of each upkeep, put your choice of a +1/+1, lifelink, menace, trample, or vigilance counter on a token creature you control.

Destroy target nonland permanent. If it had flying, put a flying counter on a creature you control. Do the same for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Whenever Thundering Towershell attacks, return a creature card with mana value 5 or less from a graveyard to the battlefield under your control. Trigger a death knell of that creature.

When Tinker Tantrum enters and at the beginning of your upkeep, you may sacrifice an artifact. If you do, reveal cards from the top of your library until you reveal an artifact card with mana value X or less, where X is 1 plus the sacrificed artifact's mana value. Put that card onto the battlefield and the rest on the bottom of your library in a random order.