msem-instigator

Vigilance
At the beginning of your end step, if you control two or more Spirits and/or creatures with flying, transform Haunted Waif.

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.

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

Menace
When Heart of the Deadwood enters, destroy up to one target creature, then put up to one target creature card from a graveyard onto the battlefield under your control.

Flying, vigilance, deathtouch, lifelink

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.)

Flying, lifelink

Trample
Whenever Heir to the Old Bonds becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.

When Helicos Aberration enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

When Helicos-Drowned Captain enters, create a black Aura Curse enchantment token named Marked for Death attached to target player. The token has enchant player and “At the beginning of enchanted player's upkeep, that player loses 1 life.”

Whenever you scry, you gain life equal to the number of cards looked at while scrying this way.

Menace, trample
Hellfreaks gets +1/+0 for each Curse you control.
Hellfreaks gets +1/+0 for each instant and sorcery card you own in exile and in your graveyard.

Whenever Herald of Earth deals combat damage to a player, draw a card.
Whenever you draw a card, put a +1/+1 counter on Herald of Earth.

Flying
Whenever Herald of Flame attacks, gain control of target permanent until end of combat. If it's a creature, you may have it become tapped and attacking.
Whenever a creature you control becomes blocked, Herald of Flame deals 3 damage to the player or planeswalker that creature is attacking.

Trample
At the beginning of your end step, if there are two or more +1/+1 counters among creatures you control, return Herald of Might from your graveyard to the battlefield.

Flying
Whenever Herald of Shadow attacks, another target creature can't be blocked this turn.
Whenever a creature you control deals combat damage to an opponent, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

Whenever a player casts a noncreature spell, create a 1/1 white Human Soldier creature token.
{1}{U}, Tap four untapped creatures you control: Counter target noncreature spell.

When Highbeam Hulk enters, you may discard a card. If you do, draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Flash
If a spell or ability an opponent controls would cause you to discard a creature card, you may put that card onto the battlefield instead.

Whenever a creature dies, exile it.
Hiroto Jaakuna has all activated abilities of creature cards exiled with Hiroto Jaakuna.

Prevent all damage that would be dealt to you and permanents you control.

Reach
When Hoarding Arachnid dies, draw a card.

Flying
When Hoarding Dragon enters, you may search your library for an artifact card, exile it, then shuffle.
When Hoarding Dragon dies, you may put the exiled card into its owner's hand.

Reveal the top three cards of your library. Put up to one creature or Revelation card from among them into your hand and the rest into your graveyard.
Coalesce {6}{G} (You may cast this from your graveyard for {6}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Hold Life in Taloned Grasp's power is equal to the number of cards in your graveyard.