msem-instigator

({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}.

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.”

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}.
{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.

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}: 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.

{T}: Add {C}.
Ascend—Tap ten untapped permanents you control. (Tap ten untapped permanents you control: Exile this land, then return it to the battlefield transformed. Ascend only as a sorcery.)

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
Equipped creature gets +3/+2.
Equip {2}

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

{T}: Add {C}.
{3}{U}: Until end of turn, I's Observatory becomes a 1/4 creature. It's still a land. It has menace if {B} was spent to activate this ability, has first strike if {R} was spent, and assigns combat damage equal to its toughness rather than its power if {G} was spent.

Ice Path enters tapped.
As Ice Path enters, choose a color.
You may spend {C} as though it were mana of the chosen color.
{T}: Add {C}.

{1}, {T}: Tap target artifact, creature, or land.

{T}: Add {C}.
{2}: Idravir becomes a 2/2 creature with undying in addition to its other types until end of turn. (When that 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.)

Idyllic Oasis enters tapped unless you control a Plains.
{T}: Add {G} or {U}.