msem-instigator

When Healing Potion enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Healing Potion: You gain 4 life.

Heart of Carü Mapu enters tapped.
{T}: Add X mana in any combination of colors, where X is the number of basic land types among lands you control.

{T}: Add {C}.
{3}, {T}: Choose a color. For each differently named land you control, add one mana of that color.

({T}: Add {G} or {W}.)
Heart of the Glade enters tapped unless you control a basic Forest or a basic Plains.

Flying, vigilance, deathtouch, lifelink

If one or more counters would be put on a creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.

Enchant creature
When Heartstrings leaves the battlefield, exile enchanted creature.
Whenever enchanted creature attacks or blocks, exile it at end of combat.

Haste
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

{T}: Add {C}.
When Heavenly Temple enters, target creature gains flying until end of turn.
{2}: Return Heavenly Temple from the battlefield to its owner's hand.

{1}, {T}: Add one mana of any color.
{1}, {T}, Sacrifice Heavy Moneybag: Post a bounty on target creature or planeswalker. Activate only as a sorcery. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

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

Whenever you cast a noncreature spell, you may put a progress counter on Hellbent Speed.
[PROGRESS 2+] Noncreature spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.
[PROGRESS 6+] Whenever you cast a noncreature spell, draw a card.

Hellfire Caverns enters tapped.
{T}: Add {R}.
{2}{R}: Until end of turn, Hellfire Caverns becomes a 3/3 Devil creature with menace. Activate only if you're horrific.

{T}: Add {C}.
{T}, Reappropriate: Add {B} or {R}. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

Equipped creature has hexproof.
Whenever equipped creature dies, draw a card.
Equip {2}

Equipped creature has “{T}: Target attacking creature gets +1/+1 until end of turn.”
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Equipped creature has base power and toughness 4/4, haste, and hexproof.
Equip {2}

{6}: Until the next time this ability resolves, and as long as Helm of the Infinite and target creature you control are on the battlefield, each other creature is a copy of that creature, and effects that would cause permanents to become creatures cause them to become copies of that creature instead.

When Helmsman's Chart enters, draw a card.
{T}: Until end of turn, target land you control becomes the basic land type of your choice in addition to its other types.

At the beginning of each end step, if a creature died this turn, you may put a +1/+1 counter on target creature you control.

Equipped creature can't attack or block.
{4}: Attach Heping's Armistice Chains to target creature you don't control.
{8}: Gain control of equipped creature.

(Transform this if it's not attached to a creature. Pay {B} as a sorcery to unattach it.)
Enchant creature you control
Herald of Death's rider gets +1/+1.
Sacrifice a creature: Herald of Death's rider gets +2/+2 until end of turn.

Lands you control are colorless lands named Wastes with “{T}: Add {C}” and lose all other card types and abilities.

(Transform this if it's not attached to a creature. Pay {4}{G} as a sorcery to unattach it.)
Enchant creature you control
Herdstrider's rider gets +1/+1 for each land you control and has trample.
Whenever Herdstrider's rider attacks, create an X/X green Elephant creature token with trample that's tapped and attacking, where X is that creature's power. Exile that token at the end of combat.

Heretic's Home enters tapped.
{T}: Add {R} or {G}.
When Heretic's Home enters, you may put a loyalty counter on a planeswalker you control.