msem-instigator

Whenever H.S.S. Demeter becomes blocked by a creature, gain control of that creature.
Whenever H.S.S. Demeter deals combat damage to a player, draw two cards.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Enchant player
Creature tokens enchanted player controls get +1/+1.

At the beginning of your end step, you may discard a creature card. If you do, you draw a card and you lose 1 life.
Whenever a creature you control attacks alone, you may cast a creature card from your graveyard. That creature enters tapped and attacking. If you do, sacrifice the creature you attacked with at end of combat.

Indestructible
Whenever Hannaru the Conqueror attacks, put a +1/+1 counter on each creature you control.

When Hannaru's Spear enters, create Hannaru's Aegis, a legendary white Equipment artifact token with “Equipped creature gets +1/+2 and has vigilance” and equip {2}.
Equipped creature gets +2/+1 and has first strike.
Equip {2}

Flying, trample
Whenever Hao'Tai, the Ancient One deals combat damage to a player, exile the top four cards of that player's library. Until end of turn, you may cast instant, sorcery, and creature cards from among those exiled cards, and you may spend mana as though it were mana of any color to cast them.

Flying
At the beginning of your first main phase, you may put any number of land cards from your hand onto the battlefield, then draw a card for each land put onto the battlefield this way.

At the beginning of your end step, exile target permanent.
When Head of Ulko leaves the battlefield, return each other card exiled with it to the battlefield under your control.

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.)

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.

Enchant creature
When Heartstrings leaves the battlefield, exile enchanted creature.
Whenever enchanted creature attacks or blocks, exile it at end of combat.

When Hellion Devastator enters, destroy up to one target nonland permanent with mana value 3 or less.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Flying, prowess
If you would draw a card, scry 1, then draw a card instead.
Whenever an opponent casts a spell, if it's not their turn, draw a card.

Flash
When Herald of Wisdom enters, you may cast target instant or sorcery card with mana value 4 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Destroy target creature or planeswalker.

Lifelink
Tap three other untapped creatures and/or artifacts you control: Transform Heroic Crusader.

First strike, lifelink
Once each turn, when another nontoken creature you control dies, you may create a 2/2 white Elk Spirit creature token with first strike and lifelink named Fawn of Hesediel.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
{T}: Add {G}.
Whenever Hierarch Ranger encourages a creature, add one mana of any color.

(Activate each ability only once as a sorcery. You gain the realm's favor after activating them all.)
{W}: Put a first strike counter on target creature.
{1}{W}: Invigorate 2. (Choose a creature with the least power among creatures you control and put two +1/+1 counters on it.)
{2}{W}: Create two 1/1 white Soldier creature tokens.
Creatures you control with counters on them have flying and lifelink.

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.

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.

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.)

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

{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.