msem-instigator

Whenever you cast a spell during an opponent's turn, Haughty Priest deals 1 damage to that player.

Haunted Estate enters tapped unless another player controls a land that could produce {W} or {B}.
{T}: Add {W} or {B}.

Haunted Woodlock enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Flying
Whenever Haunter of the Deadlands attacks, Spirit creatures you control get +1/+1 until end of turn.

Lifelink
Whenever you sacrifice a creature, you gain life equal to its power.

Enchant creature
Enchanted creature gets -1/-3.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Mirage {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.)

Menace
Sacrifice a Goblin: Heartless Warleader gets +2/+2 until end of turn.

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Flying
When Heartstabber Mosquito enters, if it was kicked, destroy target creature.

Whenever a creature blocks, Heat of Battle deals 1 damage to that creature's controller.

Shuffle your library, then reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Heathen Rise deals damage to you equal to the number of cards revealed this way.
Ferocious — That creature gains haste if it has power 4 or greater.

Vigilance
{W}: Heaven's Champion gains first strike until end of turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature you control with flying attacks, it gets +1/+1 until end of turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Heavensent Emissary enters with a +1/+1 counter on it for each other creature with flying you control.

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
When Heedless Adversary enters, you may have it deal 3 damage to target creature if that creature's controller failed the trial.

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.

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.

[+1]: Until your next turn, if a source would deal damage to Heping, Master Arbitrator, prevent all but 1 of that damage.
[–2]: Create a white Aura enchantment token named Pacifism attached to target creature an opponent controls. It has enchant creature and “Enchanted creature can't attack or block.”
[–8]: You get an emblem with “At the beginning of your end step, your life total becomes 20.”

Target player sacrifices any number of lands. That player searches their library for up to that many land cards, puts them onto the battlefield tapped, then shuffles.
Fabled {5}{G}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Flying
Whenever Heroes of Wars Past attacks, attacking Human creatures get +1/+1 and gain flying until end of turn.

[+1]: Add {G}{U}{R}. Spend this mana only to cast creature spells.
[–2]: Reveal the top card of your library. If it's a creature card that costs less than the last spell you cast this turn, you may put it onto the battlefield. Otherwise, draw a card.
[–7]: Target creature becomes a legendary 20/20 green creature named Illusion of Kaur with hexproof and trample until end of turn.

At the beginning of your upkeep, put a +1/+1 counter on Heyu, Immortal Hunter.
Whenever Heyu becomes the target of a spell or ability an opponent controls, counter it if Heyu has the greatest power among creatures on the battlefield.