msem-instigator

Whenever a creature you control dies, put a soul counter on Hill of Souls.
{T}: Add {C}.
{T}, Remove a soul counter from Hill of Souls: Add one mana of any color.

When Himari enters, put a +1/+1 counter on a creature you control.
Creatures you control with counters on them have base power and toughness 4/4 and have trample.

Reach
Art of war — At the beginning of your end step, if Hinode Ranger dealt damage to an opponent this turn, put a +1/+1 counter on it.

{2}{R}, {T}, Exert Hinterland Ritualist, Sacrifice another creature: Hinterland Ritualist deals damage equal to the sacrificed creature's power to any target. Activate only as a sorcery. (An exerted creature won't untap during your next untap step.)

This spell costs {1} less to cast for each planeswalker you control.
[+2]: Create a 2/2 colorless Spirit creature token.
[–3]: Double the number of each kind of counter on another target permanent.
[–9]: You get an emblem with “The ‘legend rule' doesn't apply to creatures and planeswalkers you control.”

If a permanent with spirited entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Reach
When Hoarding Arachnid dies, draw a card.

Flying
When Hoarding Dragon enters, you may search your library for an artifact card, exile it, then shuffle.
When Hoarding Dragon dies, you may put the exiled card into its owner's hand.

Reveal the top three cards of your library. Put up to one creature or Revelation card from among them into your hand and the rest into your graveyard.
Coalesce {6}{G} (You may cast this from your graveyard for {6}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Hold Life in Taloned Grasp's power is equal to the number of cards in your graveyard.

As Holdsteady Engine enters, choose a card name.
Cards with the chosen name entering the battlefield don't cause abilities to trigger.
Activated abilities of cards with the chosen name can't be activated unless they're mana abilities.

When Hollow Hooligan enters, up to two target creatures can't block this turn.
Mirage {1}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Defender, deathtouch
Homestead Watcher gets +2/+0 and can attack as though it didn't have defender as long as you control another creature with defender.

Equipped creature has respawn. (When this creature dies, if it attacked this turn, return it to its owner's hand.)
Equip {1}

Target creature you control fights another target creature.
Inscribe {3}{G} ({3}{G}: 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.)

{T}: Add {C}.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

Return a permanent card from your graveyard to your hand.
Motley — If there are five or more names among nonland permanents you control, return two permanent cards from your graveyard to your hand instead.

(Add a quest counter as this enters. Sacrifice after 3.)
Once each turn, when you cast a spell with mana value equal to the number of lands you control, you may add a quest counter.
You may search your library for a basic land card, reveal it, then shuffle and put that card on top. You gain 1 life for each quest counter on Hoof Cliff Expedition.
Search your library for a creature card, reveal it, put it into your hand, then shuffle.

{T}: Add {C}.
{1}: Hoof Cliff Horngrove becomes a 2/2 Elemental creature until end of turn. It's still a land.
Menagerie — Whenever Hoof Cliff Horngrove becomes a creature, it gains your choice of +1/+1, flying, first strike, lifelink, trample, or haste until end of turn. This ability triggers only if there are five or more creature types among creatures you control.

Trample, haste

Double strike
When a creature you control scavenges Hook-Style Trainee, put a double strike counter on that creature.
Scavenge {4}{R} ({4}{R}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Other Pirates you control get +1/+0.
Whenever another Pirate you control enters, Hookhand Freebooter deals 1 damage to any target.
When Hookhand Freebooter dies, create a Bullet token. (It's an artifact with “{T}, Sacrifice this artifact: It deals 1 damage to any target.)

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

Trample

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.

Horizon Wayfarer's power and toughness are each equal to the number of differently named lands you control.