msem-instigator

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life unless that player is cursed.

When Belief in the World enters, you may tap two untapped creatures you control. If you do or you control two or more Spirits, search your library for a Spirit card, reveal it, put it into your hand, then shuffle.
Creatures you control get +1/+1.

As Sunless Ridge enters, you may tap an untapped creature you control. If you don't, Sunless Ridge enters tapped.
{T}: Add {B} or {R}.

Flying
When Cloudheath Sentinel enters, return target artifact card with mana value 2 or less from your graveyard to the battlefield.

Flying, vigilance, indestructible
Faradia, Honored Sovereign can't attack or block unless you tap three other untapped creatures and/or artifacts you control.

Equipped creature gets +2/-1.
Equip {1}

Whenever a creature with a counter on it dies, create a Gold token. (It's an artifact with “Sacrifice this artifact: Add one mana of any color.”)

Foresight — Whenever you draw your second card each turn, Haggler's Hound gets +1/+1 and can't be blocked by creatures with power 2 or less until end of turn.

Colossal 3—{4}{R} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {4}{R} as a sorcery: Put three +1/+1 counters on it if it has none.)
When Storm-Eye Salamander's colossal ability puts one or more counters on it, exile the top three cards of your library. Until the end of your next turn, you may play one of those cards.

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Target creature you control gains protection from everything until end of turn.

{T}: Add {C}.
Whenever Cunning Chanter becomes tapped, each opponent mills a card.

When Jara Disciplinarian enters, each player sacrifices a creature.

When Forserval enters, creatures you control get +1/+1 and gain haste until end of turn.

Senaturian Legion gets +1/+1 for each other creature on the battlefield named Senaturian Legion.
A deck can have any number of cards named Senaturian Legion.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
{2}{G}, {T}: Create a token that's a copy of target creature token.

When Vale Ruins enters, you gain 1 life.
{T}, Sacrifice Vale Ruins: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

[+1]: Create a 1/1 white Warrior creature token.
[–1]: Another target permanent you control gains indestructible until your next turn.
[–8]: You get an emblem with “Creatures you control get +2/+2.” and “Prevent all damage that would be dealt to attacking creatures you control.”

{1}{U}, {T}: Draw a card, then discard a card.

Identity — As long as you control at least two other creatures that share a creature type with Danuri Eaglerider, Danuri Eaglerider gets +1/+2 and has flying.

First strike
Whenever Zankon, Ema's Claws blocks or becomes blocked, put a +1/+1 counter on each creature you control.

When Aethermancer's Companion enters, aetherize up to two other non-Cat permanents you control. (Create tokens that are copies of each of them, then exile them.)
Recite {5}{W}{U} (You may cast this spell from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

{T}, Sacrifice an artifact or enchantment: Draw a card.

Target creature gets +3/+1 and gains trample until end of turn.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Blessed Vanquisher encourages a creature, destroy target creature an opponent controls if it's tapped. Otherwise, tap that creature.