msem-instigator

Hartwin, Cunning Lieutenant can't block.
If spell or ability would cause an opponent to discard a card, instead that player discards a card at random. When a nonland card with mana value 2 or less is discarded this way, you may cast it without paying its mana cost.

When Harvest Blighter enters, create a black Aura Curse enchantment token named Rotting Away attached to target player. The token has enchant player and “Whenever a creature enters under enchanted player's control, if it has toughness 2 or greater, put a -1/-1 counter on that creature.”

Vigilance
Invocation — Whenever you spend four or more mana to cast a spell or activate an ability during your turn, you gain 2 life.

Reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever one or more tokens you control enter, put a +1/+1 counter on Harvesttide Nemesis. This ability triggers only once each turn.

When Hate-Driven Arsonist enters, you may have it deal X damage to target creature or planeswalker, where X is the number of instant and sorcery cards in your graveyard.

{W}: Target creature assigns combat damage equal to its toughness rather than its power this turn.

When Haunted Heirloom dies, create a Treasure token.

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

Flying
Whenever Haunting Horseman deals combat damage to a player, that player discards a card.

Whenever Haunting Maestro attacks, you may tap or untap up to two target creatures.

Untap all other Elves you control during each other player's untap step.
You may cast spells as though they had flash.

Flying
Whenever Havengul Banshee attacks, each creature defending player controls gets -1/-0 until end of turn.
{3}{U}: Return Havengul Banshee from your graveyard to the battlefield transformed under your control attached to target opponent. Activate only as a sorcery.

Ward—Sacrifice a permanent.
Whenever a player sacrifices a permanent, put a +1/+1 counter on Hayat, Hungering Bakhtak.
Surpass {4}{B}{G} ({4}{B}{G}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Whenever you cast an instant or sorcery spell, look at the bottom card of your library. You may manifest it. If you don't, put it into your hand. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

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.)

Reach
When Headhunter Mantis enters, if a creature you controlled died this turn, create a 1/1 green Insect creature token.

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.

Flying
When Heartless Host enters, arm target creature. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

At the beginning of your upkeep, if you have less life than an opponent, you lose 1 life and you draw a card.

Deathtouch
Whenever another creature dies, its controller discards a card at random.

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 you attack, you may pay {R}{W}. If you do, create a tapped and attacking token that's a copy of target attacking creature. Sacrifice the token at the beginning of the next end step.

Reach

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.)

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.