msem-instigator

When Rigid Conformist enters, for each {W} spent to cast it, create a 1/1 white Human creature token.
Each creature you control gets +2/+2 if you control another creature with the same name as that creature.

When Trenchbottom Mariners enters, you lose 3 life, mill three cards, and create a Treasure token.
Whenever Trenchbottom Mariners attacks, you may cast a permanent card from your graveyard by sacrificing another artifact in addition to paying its costs.

Target creature you control and each other creature in its pack deal damage equal to their power to target creature or planeswalker. (Two or more creatures you control with equal power are in a pack.)

Frilled Hydra enters with X +1/+1 counters on it.
Defiance (Whenever this creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)
Frilled Hydra has hexproof as long as it's defiant.

Flying
{2}, Exile an instant or sorcery card from your graveyard: Spellbone Screecher deals 1 damage to any target.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{2}, Discard your hand: Unlock Traitor's Gambit. If the revealed card is red, put it into your hand. Otherwise, put it on top of your library.

Scry 1. Draw a card. Scry 1.

At the beginning of your end step, mill two cards. Then if ten or more cards are in your graveyard, transform Bitter Duckling.

When Reha, Entropy's Call enters, you may search your library for any number of land cards with different names and exile them with harvest counters, then shuffle.
At the beginning of your upkeep, you may put a card that you own in exile with a harvest counter on it at random onto the battlefield tapped.

As an additional cost to cast this spell, tap three untapped creatures you control with power 1 or less.
Search your library for a creature card, put it onto the battlefield, then shuffle.

Prowess
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

Whenever you cast a spell that doesn't share a color with Stinging Hunter, each opponent loses 1 life.

Lifelink
Menagerie — When Leafdown Glimmerfox enters, if there are five or more creature types among creatures you control, exile another target nonland permanent until its controller's next end step.

{T}: Add {B}, {R}, or {G}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Target creature gains lifelink until end of turn. Untap that creature.
Inscribe {1}{W} ({1}{W}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Players can't sacrifice creatures to cast spells or activate abilities unless that player sacrifices an additional creature. The same is true for discarding cards and paying life.

When Lisa, the Daughter enters, create Mother, a legendary 4/1 black Demon creature token with flying and “This creature can't block.”
If a source would deal damage to Lisa while you control a Demon creature, instead that damage is dealt to a Demon creature you control of your choice.

As this permanent transforms into The All-Consuming Swarm, counters on her become loyalty counters instead.
[+2]: Create three 1/1 black and green Insect creature tokens with flying.
[–3]: For each permanent type, each opponent sacrifices a permanent of that type.

Whenever a creature attacks one of your opponents, that player loses 1 life.

Whenever Lightseeker Nymph perseveres, search your library for a basic land card, put it onto the battlefield tapped, then shuffle. (A creature perseveres when it survives damage.)

Skavi Behemoth can't be the target of nongreen spells or abilities from nongreen sources.

As an additional cost to cast this spell, tap any number of untapped storied permanents you control.
Return X target creatures to their owner's hand, where X is one plus the number of permanents tapped this way.

Whenever Field Chaplain perseveres, you gain 3 life. (A creature perseveres when it survives damage.)

When Astute Sceneweaver enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flash
Flying
When Angel of Redemption enters, if another target creature you control would die this turn, exile it instead. Return that card to the battlefield under its owner's control at the beginning of the next end step.