msem-instigator

When Improvisionist enters, if it was the second spell you cast this turn, exile the top card of your library. You may play that card until the end of your next turn.

Advance {1}{R}{R} (Cast this for {1}{R}{R} to advance it as it enters. {1}{R}{R}: Advance this as a sorcery.)
Whenever Impulse Module enters or advances, put a charge counter on it, then exile a card from the top of your library for each charge counter on it. Until your next turn, you may play one of those cards.

Exile the top card of your library. Impulsive Action deals damage to any target equal to that card's mana value plus one. Until end of turn, you may play that card.

Enchant creature
Whenever enchanted creature deals combat damage to a player, exile the top card of your library. Until end of turn, you may play that card.

Enchant creature
Enchanted creature has “Whenever this creature attacks, if there are at least two other attacking creatures, this creature gains +2/+2 until end of turn.”

Enchant creature
Whenever enchanted creature attacks, up to two target creatures can't block this turn. Up to one target creature blocks this turn if able.

Draw two cards, then you may put a land card from your hand onto the battlefield. If you cast In Dire Straits during your turn for its reconstruct cost, create X 3/2 green Horror creature tokens, where X is the number of lands you control.
Reconstruct {8}{G}{G}{U}{U} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

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.

This spell costs {2} less to cast if there's a storied card in your graveyard. (Enchantments and legendary cards are storied.)
Search your library for a storied card, reveal it, put it into your hand, then shuffle.

Escalate {G} (Pay this cost for each mode chosen beyond the first.)
Choose one or both —
• Target creature you control gains deathtouch and indestructible until end of turn.
• Target creature you control fights target creature you don't control.

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
Search your library for an Angel card, reveal it, put it into your hand, then shuffle. If the trial was failed, non-Angel, non-God creatures can't attack or block until your next turn.

Target creature you control gets +2/+2 until end of turn.
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.”)

Enchant creature
When Inborn Instincts enters, enchanted creature deals damage equal to its power to target creature an opponent controls.
Enchanted creature gets +6/+6.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Whenever this creature attacks, target creature blocks it this combat if able.

When Incantation Demon enters, return target instant or sorcery card from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature can't attack or block.
At the beginning of your upkeep, you gain 1 life.

Destroy target tapped creature. You gain 2 life.

This spell costs {1} less to cast for each tapped creature you control.
Whenever Incarnation of Enmity attacks, each other attacking creature gets +1/+0 until end of turn.

When Incense Stoker enters, you may return target instant or sorcery card with mana value less than or equal to the number of differently named lands you control from your graveyard to your hand.

{R}, Tap two untapped artifacts you control: Incineration Expert deals 1 damage to any target.
{3}{R}, Tap eight untapped artifacts you control: Incineration Expert deals 8 damage to any target.

Haste
When Inciter of Spirits Scorned enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains haste. Sacrifice it at the beginning of the next end step.

Haste
When Inciting Bard enters, other creatures you control get +1/+0 and gain haste until end of turn.

Equipped creature gets +3/+2 and must be blocked by a creature that doesn't share a color with it if able.
Equip {4}

Each opponent loses 1 life and you gain 1 life. Surveil 2.
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.”)

Advance {3}{W}{W} (Cast this for {3}{W}{W} to advance it as it enters. {3}{W}{W}: Advance this as a sorcery.)
Whenever Inconspicuous Loxodon advances, search your library for an Equipment card, put it onto the battlefield, then shuffle.
As long as Inconspicuous Loxodon is enchanted or equipped, he's a 5/5 legendary Elephant Rogue named Agent E.