msem-instigator

Haste
{2}{W}, {T}: Hair-Trigger Marshall deals 2 damage to target blocking creature.

Survivors you control get +1/+1.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{1}, Sacrifice two Clues: Unlock Hall of Lost Histories and put the revealed card into your hand.

{T}: Add {C}.
{3}, {T}, Sacrifice Hall of Random Access Memories: Return target artifact, instant, or sorcery card from your graveyard to your hand.

{T}: Add {C}. You gain 1 life.

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if you have a counter.

When Halskrow Street Scavenger enters, if a creature died under your control this turn, create a 2/2 green Wolf creature token.

When Hamlet Bounder enters, choose one —
• Destroy target artifact or enchantment.
• Create a 1/1 white Peasant creature token.

Hexproof
Deploy 4 (As this enters, you may tap any number of other creatures you control with total power 4 or more.)
When Hamlet Witch enters deployed, return target card from your graveyard to your hand.

When Hand of Fury enters, it gets +2/+2 and gains haste until end of turn.
At the beginning of your upkeep, if your fealty to Mountains is five or greater, transform Hand of Fury. (Each Mountain you control counts towards your fealty to Mountains.)

You don't lose unspent mana as steps and phases end except at end of turn.
Hand of the Chroma gets +1/+1 for each color of unspent mana you have.

Equipped creature has menace.
Whenever equipped creature attacks, it gets +X/-X until end of turn, where X is a number of your choice less than its toughness.
Equip {2}

Trample
At the beginning of your upkeep, if your fealty to Forests is five or greater, transform Hand of the Harvest. (Each Forest you control counts towards your fealty to Forests.)

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Menace

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
Whenever Hao'Tai deals combat damage to a player, that player exiles the top five cards of their library and separates them into two piles. Put an ember counter on each card in the pile of your choice. You may play cards from exile with ember counters for as long as they remain exiled.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)
Whenever Haploc Striker attacks and isn't blocked, you may cast target instant or sorcery card from your graveyard if its mana value is less than or equal to Haploc Striker's power. Exile that card instead of putting it into your graveyard as it resolves.

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.

When Harbinger of Growth enters, create a 1/1 green Saproling creature token.
{1}{G}, Sacrifice Harbinger of Growth: Populate. (Create a token that's a copy of a creature token you control.)

When Hardened Explorer enters, choose one —
• Destroy target artifact.
• Put a +1/+1 counter on Hardened Explorer. It gains haste.

As Harlowe, Thespian Extraordinaire enters, choose a color and creature type.
Harlowe, Thespian Extraordinaire is the chosen color.
Harlowe, Thespian Extraordinaire is the chosen type in addition to its other types.

Exile the top three cards of your library. When you do, choose one —
• You may play those cards until the end of your next turn.
• Exchange your hand and the exiled cards.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. Put a +1/+1 counter on each creature you control.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{3}{G}: Harmonic Recruit gets +2/+2 until end of turn. If you're in a renaissance, it gets +4/+4 until end of turn instead.

{2}, {T}: Target opponent exiles a nonland, nontoken permanent they control.
{2}, {T}: Put target permanent card exiled with Harmony Array onto the battlefield under your control.