msem-instigator

Whenever a nontoken creature you control dies, create a 1/1 black Spirit creature token with flying.
[+1]: Each opponent loses 2 life and you gain 2 life.
[–2]: You may sacrifice a creature. When you do, destroy target nonland permanent.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
Whenever you cast a spell that doesn't share a color with Cloudstep Capuchin, Cloudstep Capuchin gains flying and hexproof until end of turn.

When Obscure Apostle enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Whenever you sacrifice an Idol, Obscure Apostle can't be blocked this turn.

Creatures you control with flying get +1/+1.
Whenever a creature you control with flying deals combat damage to a player, you may pay {U}. If you do, draw a card.

Bulwark — Whenever Soulstone Servant attacks, if you control a creature with toughness 4 or greater, Soulstone Servant gets +2/+2 and gains flying until end of turn.

Hollow Queen can't be blocked by tokens.
Whenever Hollow Queen deals combat damage to a player or planeswalker, you may remove a counter from a permanent you control. If you do, put a +1/+1 counter on target creature you control.

Whenever a creature you control deals combat damage to a player or planeswalker, you may pay {W} and/or {U}. When you pay {W} this way, put a +1/+1 counter on target creature you control. When you pay {U} this way, draw a card.

Rapport — Whenever Witch's Apprentice and at least one other creature you control become tapped, Witch's Apprentice gets +1/+1 until end of turn, then scry 1.

When Pilgrim of Many Provinces enters, draw a card. Then you may discard a creature card. If you do, draw a card.

Permanents you control gain indestructible until end of turn. Untap each creature you control.
Cycling {W} ({W}, Discard this card: Draw a card.)

Vigilance
When Tortle Guard enters, it 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 this creature, then you may put that card in your graveyard.)

Each creature you control that's enchanted or is an enchantment gets +1/+1.
{2}{W}{W}: You may reveal an enchantment card you own from outside the game and put it into your hand.

{1}, {T}, Exile a creature card from your graveyard: Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Vigilance
This spell costs {1} less to cast for each +1/+1 counter among creatures you control.

Deathtouch
Inspired — Whenever Yenzu Nightblade becomes untapped, target creature you control gets +1/+1 and gains deathtouch until end of turn.

Whenever Weathered Skiff attacks, it gets +1/+1 until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Reach
When Hoarding Arachnid dies, draw a card.

{T}: Add {C}.
{4}{U}, {T}: Draw a card.
At the beginning of your end step, if you have eight or more cards in your hand, you may pay {5}{U}{U} and exile this land. When you do, take an extra turn after this one.

{T}: Choose a color of a card in your graveyard. Add one mana of that color.

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Creatures you control get +2/+2.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

When Artian, Phyrexian Architect enters, search your library for a land card, put it onto the battlefield, then shuffle.
At the beginning of your upkeep, put a corruption counter on a land you control. Then create a 1/1 colorless Phyrexian artifact creature token for each land you control with a corruption counter on it.

Whenever Tide Crasher attacks, if you control another Merfolk, tap target creature defending player controls.

Enchant player
Whenever Curse of the Tattletale or another Curse becomes attached to enchanted player, each of their opponents draws a card.

Pressure {3}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Put two +1/+1 counters on target creature you control if Way of the Danithra was cast for its pressure cost. Then it fights up to one target creature you don't control.