msem-instigator

Flying
If a source would deal damage to an opponent, it deals double that damage to that player instead.

Flying
Whenever Hellkite Omnivore attacks, you may have it consume. If you do, put a +1/+1 counter on Hellkite Omnivore. When a creature is sacrificed this way, Hellkite Omnivore deals 3 damage to any target. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Hellkite's Decree deals 3 damage divided as you choose among one, two, or three target creatures and/or planeswalkers.
Cycling {2} ({2}, Discard this card: Draw a card.)

Haste
The first instant or sorcery spell you cast each turn costs {1} less to cast.
{R}, {T}, Sacrifice Hellspark Prankster: Change the target of target spell with a single target.

Elemental, instant, and sorcery spells you cast cost {1} less to cast.

Flying, haste
Whenever you attack with three or more creatures, harmonize three times. (To harmonize, trigger up to one harmony of a permanent you control.)
If you would harmonize, you may instead return Herald of Festivities from your graveyard to your hand.

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.

Haste
{1}{R}, {T}: Attacking creatures you control get +1/+0 until end of turn.

Haste
Whenever Herald of the Humble deals combat damage to a player, that player reveals the top card of their library. If it's a nonland card with mana value 3 or less, they may cast it without paying its mana cost.

Target opponent may draw two cards. If they do, you draw four cards. Otherwise, you create four 1/1 red Elemental creature tokens.

Whenever Hero of Aer attacks, it gets +2/+1 until end of turn.

Equipped creature gets +3/+1 and has haste.
Equip Soldier or Warrior {1}
Equip {4}

Whenever you cast a spell that's white, blue, black, or green, put a +1/+1 counter on Hesitant Vanguard.
Surpass {5}{R} ({5}{R}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Scry 2, then create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Monument {2}{R} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Hidden Prowess deals 2 damage to target creature. When that creature dies this turn, create a 1/1 red Elemental creature token.

Prowess
Whenever High Rollers Croupier attacks, you may put a lore counter on a Saga you control.

Flash
Prowess
When High Rollers Esteemed enters, you may choose new targets for target spell or ability unless its controller has High Rollers Esteemed deal 4 damage to them.

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

{2}{R}, {T}, Exert Hinterland Ritualist, Sacrifice another creature: Hinterland Ritualist deals damage equal to the sacrificed creature's power to any target. Activate only as a sorcery. (An exerted creature won't untap during your next untap step.)

{1}{U}, Tap an untapped Noble you control: Hired Blades gets +2/+1 until end of turn and can't be blocked this turn.

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.

When Hollow Hooligan enters, up to two target creatures can't block this turn.
Mirage {1}{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.)

Trample, haste

Double strike
When a creature you control scavenges Hook-Style Trainee, put a double strike counter on that creature.
Scavenge {4}{R} ({4}{R}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Other Pirates you control get +1/+0.
Whenever another Pirate you control enters, Hookhand Freebooter deals 1 damage to any target.
When Hookhand Freebooter dies, create a Bullet token. (It's an artifact with “{T}, Sacrifice this artifact: It deals 1 damage to any target.)