msem-instigator

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Abhorrent Exhumer enters, if it engorged a creature card, you may return target creature card from your graveyard to your hand.

Destroy target creature with power 4 or greater.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Deathtouch
Cards can't leave graveyards.
If a creature would die, you may pay {X}, where X is the number of cards in your graveyard. If you do, instead exile it, then return that card to the battlefield under your control.

When Brand New Species enters, create a tapped 3/2 green Horror creature token.
Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on up to one target Horror you control.

Defender
Whenever another player casts an instant or sorcery spell, Devouring Spellroot gets +2/+2 until end of turn.

Destroy target creature. Then if you control a Wizard, that creature's controller loses 1 life for each creature card in their graveyard.

Flying
When Sigarda's Shepherd enters, another target creature you control gets +1/+1 and gains indestructible until end of turn.

Primal {B}{B} (During your turn, you may cast this spell for {B}{B} instead of playing a land.)
Search your library for a card and put that card into your hand, then shuffle. Exile Deceitful Tutor.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
At the beginning of your end step, you may choose a cursed opponent. If you do, draw a card unless that player pays 2 life for each Curse attached to them.

Look at the top eight cards of your library. You may reveal up to one Elf and up to one Dwarf card from among them. Put the revealed cards into your hand and the rest on the bottom of your library in a random order. Tenuous Alliance deals 2 damage to you.

Heroic — Whenever you cast a spell that targets Thassa's Shoreguards, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.
Whenever Thassa's Shoreguards deals combat damage to a player, draw a card.

When Kiri Yoroi enters, create a 2/2 colorless Spirit creature token and attach Kiri Yoroi to it.
Equipped creatures you control get +1/+1.
Equip {2}

Exchange control of two target permanents that share a permanent type.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

{3}{W}: Tap target creature. Activate only during your turn.

Koth's Retaliation deals 4 damage to target creature. When that creature dies this turn, exile its controller's graveyard.

Reach, trample
Deploy 6 (As this enters, you may tap any number of other creatures you control with total power 6 or more.)
When Glaistig of Wild Hunts enters, if it was cast and deployed, untap all lands you control.

Whenever one or more nontoken Merfolk you control attack, create a 2/1 red Merfolk creature token.

Sunswept Grange enters tapped. When it enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {R} or {W}.

{1}{R}: Crashcaller Nereid gets +1/+0 and gains trample until end of turn.

At the beginning of each player's end step, that player chooses from among nonland permanents they control an artifact, a creature, an enchantment, and a planeswalker, then sacrifices the rest.

Look at the top four cards of your library. You may reveal a noncreature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Trample
{2}{G}{G}: Put Canal Lurker from its owner's graveyard on top of its owner's library.

Flash
Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control.

Menace
{1}{B}{R}: Creatures you control get +1/+0 until end of turn.

({T}: Add {B} or {R}.)
Lavatorn Fields enters tapped unless you control a basic Swamp or a basic Mountain.