msem-instigator

{T}: Add one mana of any color.
{7}, {T}, Sacrifice Hero's Statue: Draw three cards.

At the beginning of your upkeep, put a charge counter on Hexstone.
{T}, Sacrifice Hexstone: Choose a nonland permanent type. Destroy each permanent of the chosen type with mana value less than or equal to the number of charge counters on Hexstone.

Hibernation Den enters tapped.
{T}: Add {W}.
{W}, {T}: You gain 1 life. Activate only as a sorcery and only if you control a white creature.

{T}, Sacrifice Hidden Garden Entrance: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Monument {W}{U}{B}{R}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice Hidden Hollow: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

({T}: Add {R}.)
As Highland Dunes enters, you may pay 1 life. If you don't, Highland Dunes enters tapped.

({T}: Add {R} or {G}.)
Highland Vale enters tapped.

Highpoint Shrine enters tapped unless you played it from exile.
{T}: Add {W} or {U}.

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.

Hiroto's Refuge enters tapped.
When Hiroto's Refuge enters, you may mill two cards.
{T}: Add {G} or {W}.

When Hitana's Implements enters, draw a card.
{1}, {T}: Add one mana of any color.
Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} on spells this turn, exile Hitana's Implements. If you do, create a 5/5 blue Horror creature token.

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.

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

{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.)

{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.

When you attain Hopeless Lanonshee, create two 1/1 black Construct artifact creature tokens.
Whenever a creature dies, each opponent loses 1 life and you gain 1 life.

As Horizon of Origins enters, you may reveal an Island or Mountain card from your hand. If you don't, Horizon of Origins enters tapped.
{T}: Add {U} or {R}.

When Horn of Seasons enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equipped creature gets +3/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

No more than two creatures can attack each combat.

{T}: Target player exiles a card from their graveyard. If they do, you gain 1 life.

{T}: Add {C}.
{1}, {T}, Sacrifice House of Forgotten Whispers: Draw a card.

Hozen Shrine enters tapped.
{T}: Add {U} or {B}.
{U/B}, {T}, Sacrifice Hozen Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Hub of Innovation enters tapped.
At the beginning of your upkeep, if you control five or more artifacts, draw a card.
{T}: Add {C}.

As Humble Abode enters, choose a creature or planeswalker type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast spells of the chosen type.

Humble Bridge enters tapped.
{T}: Add {R} or {W}.
When Humble Bridge enters, you may put a loyalty counter on a planeswalker you control.