msem-instigator

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
At the beginning of your end step, He of All Hallow's Eve deals damage equal to its power to you unless you're horrific. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Head on Collision deals 2 damage to any target.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

Cast this spell only if you control a legendary creature or if you control six or more lands.
Exile a planeswalker card you own from outside the game. You may cast that card this turn.

Menace
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{R}: Another target creature you control gains menace until end of turn.

Trample
Whenever you cast a noncreature spell, crystallize. If you create a Treasure this way, Heartforge Savant deals 1 damage to you for each Treasure you've created this turn. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{X}{R}: Hearth Dweller gets +X/+0 until end of turn.

Menace
If another Dwarf or Elf you control would deal damage to an opponent or permanent an opponent controls, it deals that much damage plus 1 instead.
{2}{R}: Create a 1/1 red Dwarf creature token.

Reach

Heat Blast deals X damage to target creature or planeswalker.

Heat Ray deals X damage to target creature.

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

Until end of turn, gain control of target creature and it gains haste and shimmer. Untap it. (Whenever it attacks this turn, create a tapped and attacking token that's a copy of it. Exile that token at the beginning of the end step.)

Heated Dispute deals 3 damage to any target.
Ferocious — This spell costs {2} less to cast if you control a creature with power 4 or greater.

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.

Whenever a creature in Heaven's Fire Ascetic's pack attacks, that creature deals 1 damage to defending player. (Two or more creatures you control with equal power are in a pack.)

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Whenever this creature attacks, if it's merged with another card or token, it deals 2 damage to target player or planeswalker.

Choose one —
• Create two 1/1 white Soldier creature tokens. They gain haste until end of turn.
• Destroy target nonbasic land.

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.

Rogues and Pirates you control have haste.
Whenever one or more creatures you control deal combat damage to a player, exile the top card of your library. You may play that card this turn.

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

Destroy target artifact or land. If a land was destroyed this way, its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Target opponent may have you draw X cards. If they don't, reveal the top X cards of your library. Hell's Verdict deals damage to that player equal to the total mana value of cards revealed this way.

Trample
Whenever Hellfire Titan enters or attacks, exile the top card of your library and up to one target instant or sorcery card with mana value 3 or less from your graveyard. Until the end of your next turn, you may play those cards.

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.