msem-instigator

Whenever High-Priestess Nebti attacks or blocks, create a 2/2 white Cat creature token.
{1}{R}{R}, Tap an untapped Cat creature you control: That creature fights target creature you don't control.

{T}: Add {G}.
Dominance — {T}: Add {G}{G}. Activate only if you control the creature with the greatest power or tied for the greatest power.

Whenever Highpeak Rider attacks, search your library for a land card and put it onto the battlefield, then shuffle. Sacrifice that land at the beginning of the next end step.

Flying
You may look at the top card of your library any time.

Assault {B} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Hilaback Outriders assaults, it gains menace until end of turn.

When Hired Kalak enters, put target card from your graveyard on top of your library.

Civilized — As long as you control an artifact, a creature, and an enchantment, prevent all combat damage that would be dealt to Hirsute Champion.

At the beginning of your upkeep, each opponent mills cards equal to the number of card types among permanents you control.

First mate—Each nonland card in your starting deck has the same name as exactly one other card in your starting deck. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Vigilance
Whenever you cast a spell with the same name as a card in your graveyard, draw a card.

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.

While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

When Honored Retinue enters, choose a creature you control. You may search your library for a creature card with the same name as that creature, reveal it, put it into your hand, then shuffle.

When Hooded Inquirers enters, draw two cards.

When Hoof Cliff Caretaker enters, return target card of an opponent's choice from your graveyard to your hand.

Lifelink
Whenever you gain life, you may transform Hopeful Caretaker. If you don't, put a +1/+1 counter on it.

Armed — Whenever Hordedriver Enthusiast attacks, if it's equipped, creatures you control get +1/+0 and gain trample until end of turn.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
Whenever you cast an instant or sorcery spell, scry 1, then Horizon Augur gets +1/+1 until end of turn.

Flying, vigilance
At the beginning of your end step, if a creature you control dealt combat damage to an opponent this turn, put a +1/+1 counter on Horizon Prophet.

Flying, haste
At the beginning of each of your postcombat main phases, you may cast an instant or sorcery card from your graveyard with mana value less than or equal to the number of creatures that dealt combat damage to opponents this turn without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

When Host of Nature enters, create two 2/2 red and green Elk creature tokens.

Whenever you cast a noncreature spell, any number of target creatures you control get +1/+1 until end of turn.
Whenever a creature you control deals an amount of combat damage exactly equal to its mana value to a player or planeswalker, draw a card.

Other untapped creatures you control have indestructible.
{2}{G}{W}: Target creature gains vigilance until end of turn.

When Humble Archivist enters, you may return target instant or sorcery card from your graveyard to your hand. If you do, conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

At the beginning of each opponent's end step, that player loses 1 life for each creature they control unless they sacrifice a creature. Then they lose 1 life for each card in their hand unless they discard a card.

First strike
When Hunted Haunt dies, create a 1/1 black Scout creature token.