msem-instigator

When Enter the Wormhole enters or leaves the battlefield, draw a card.
Whenever you cast a noncreature spell, target player mills a card.

Vanishing 3 (This permanent enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Remove a time counter from Dwindling Stores: Add one mana of any color.

Target creature gets -3/-3 until end of turn. You gain 3 life.

Whenever Culling Claw attacks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Whenever Inkwell Daggers enters or attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
When Dancer of the Great Current enters, tap up to one target creature. If you control two or more other creatures that are Merfolk, Wizards, or Rogues, instead return that creature to its owner's hand and put a +1/+1 counter on Dancer of the Great Current.

Roggar's Gambit deals 2 damage to any target.
Reprise {1}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)
Damage dealt by sources reprising Roggar's Gambit can't be prevented.

Choose one —
• Target creature gets +0/+3 until end of turn.
• Exile target creature you control. For as long as it remains exiled, you may cast it, and it costs {2} less to cast.

Whenever Borsuppa Roughrider attacks, create a colorless Desert land token named Scoured Path with “{T}: Add {R}.” Sacrifice that token at the beginning of the next end step.

Blazing Outro deals 4 damage to any target. Then you may tap an untapped Wizard you control. If you do, cast an instant or sorcery card with mana value 4 or less from your graveyard without paying its mana cost. If it has {X} in its mana cost, X is 4. If that spell would be put into a graveyard, exile it instead.

At the beginning of combat on your turn, create a 1/1 red Nomad creature token with haste.
At the beginning of your upkeep, if you control five or more creatures, you may transform Emerabi and Sunnula.

Whenever an enchantment you control enters, draw a card. This ability triggers only once each turn.
As long as you control three or more enchantments, Nykthos Enchantress gets +2/+2 and has vigilance.

Target creature you control deals damage equal to its power to target creature you don't control.

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.

[+1]: Create a 1/1 blue Elemental creature token with flying, then crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure.)
[–3]: Exile target nonland permanent. As long as it's exiled, its owner may pay {W}{U}{B}{R}{G} as a sorcery to put it into their hand.
[–7]: You get an emblem with “Pay 1 life: Add one mana of any color.” Then you gain 100 life.

Choose one —
• Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.
• Until end of turn, if a creature would enter and it wasn't cast, exile it instead.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Other Warriors you control have first strike.
Other Barbarians you control get +1/+0.

Draw two cards. Then if this spell wasn't cast from your hand, create a Function token with “Compose.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)
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.”)

Exile target nontoken permanent you control, then return that card to the battlefield under its owner's control.

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}: Target player mills two cards.

When Keeper of Pearls enters or a creature you control scavenges it, you gain 2 life.
Scavenge {G} ({G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Lumbering Stoneshell has hexproof as long as it's untapped.