msem-instigator

Flying, haste
At the beginning of each of your postcombat main phases, you may cast an instant or sorcery card from your graveyard with mana value less than or equal to the number of creatures that dealt combat damage to opponents this turn without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

Horizon Wayfarer's power and toughness are each equal to the number of differently named lands you control.

As Horizon of Origins enters, you may reveal an Island or Mountain card from your hand. If you don't, Horizon of Origins enters tapped.
{T}: Add {U} or {R}.

You may put a permanent card from your hand onto the battlefield.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Trample
Whenever Horrific Progenitor deals damage to a player, for each damage dealt, that player loses 3 life unless they sacrifice a nonland permanent or discard a card.

Haste
When Horse Thief enters, you may gain control of target creature or Steed until end of turn. It gains haste until end of turn. If it's a Steed, attach it to Horse Thief.

Hostile Habitat deals 2 damage to each creature.
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.)

Target player creates two 1/1 white Spirit creature tokens with flying.
Fabled {3}{W}{W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Menace
Whenever an opponent activates an ability of a permanent, if it isn't a mana ability, Howling Shieldbreaker deals 2 damage to that permanent or player.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
{T}, Tap an untapped creature you control: Add one mana of any color.
{G}: Demigod — Whenever you cast a creature spell this turn, draw a card.
{4}{G}{G}: God — Creatures you control get +3/+3 and gain trample until end of turn.

Hub of Innovation enters tapped.
At the beginning of your upkeep, if you control five or more artifacts, draw a card.
{T}: Add {C}.

First mate—Your starting deck contains only cards with mana value 0, 1, or 3. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Menace
Once each turn, when one or more sources you control deal damage, you may put a +1/+1 counter on Hugo.

Menace
Whenever Hui Zhou, the Dark Visage perseveres, you may destroy another target legendary creature. (A creature perseveres when it survives damage.)

Humble Bridge enters tapped.
{T}: Add {R} or {W}.
When Humble Bridge enters, you may put a loyalty counter on a planeswalker you control.

Lifelink
Whenever another creature you control enters, Hungering Cult deals 3 damage to it.

Target creature you control gets +X/+X until end of turn. It fights target creature you don't control.

Trample
When Hunted Sprareos dies, create a 6/6 green Wurm creature token with trample.

You may cast Hunter of the Moon-Serpent from your graveyard as long as you gained life this turn.

{1}{G}{G}, Discard a card: Destroy target artifact or enchantment.
At the beginning of your end step, if twelve or more cards are in your graveyard, create two 3/3 green Beast creature tokens.

Scry 3, then reveal the top card of your library. If it's a creature card, Hunter's Instinct deals damage to target creature equal to the revealed card's power.
Ferocious — If the revealed card is a creature card with power 4 or greater, put it into your hand.

Enchant opponent
Spells you cast that target enchanted player cost {2} less to cast.

When Hunting Ground enters, create four 1/1 green Saproling creature tokens.
Whenever a creature you control dies, creatures you control get +1/+1 until end of turn.

[+1]: Prevent all damage that would be dealt to up to one other target permanent until your next turn.
[–2]: Target creature gets +3/+3 until your next turn.
[–3]: Untap all nonland permanents you control.

Target creature you control becomes a white Bear with base power and toughness 3/5, hexproof, and double strike until end of turn. Whenever it deals combat damage to a player this turn, draw a card.

Archive 6 (As this enters, shuffle the top six cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
You may play Aura and Equipment cards from the archived library, and play those spells as though they had flash.