msem-instigator

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Pressure {U} (You may cast this spell for its pressure cost if there are seven or more cards in your graveyard.)

Armed — Whenever Hordedriver Enthusiast attacks, if it's equipped, creatures you control get +1/+0 and gain trample until end of turn.

When Horizon Gazer enters, reveal the top two cards of your library. Put a noncreature card revealed this way into your hand and the rest into your graveyard.
Ascend {3}{G} ({3}{G}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Flying, vigilance
At the beginning of your end step, if a creature you control dealt combat damage to an opponent this turn, put a +1/+1 counter on Horizon Prophet.

Trample
Harmony — Put a +1/+1 counter on target Warrior you control. You gain 1 life.
Whenever one or more Warriors you control deal combat damage to a player, harmonize. (Trigger up to one harmony of a permanent you control.)

When Horn of Seasons enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equipped creature gets +3/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Tap an untapped Desert you control: Hostile Atmosphere deals 1 damage to any target.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Lifelink

Flash
When Hostile Takeover enters, you may counter target noncreature spell.
At the beginning of your upkeep, you may put a progress counter on a Project you control.

Up to one target creature gains flying until end of turn. (Then exile this card. You may cast the creature later from exile.)

This spell costs {1} less to cast for each creature that attacked this turn.
Hot to the Touch deals X damage to any target.

Whenever you make first contact, Hotshot Renegade deals 2 damage to up to one target creature or planeswalker. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Target blocking creature gets +7/+7 and gains indestructible until end of turn. You get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

{T}: Add {C}.
{1}, {T}, Sacrifice House of Forgotten Whispers: Draw a card.

Advance {2}{W} (Cast this for {2}{W} to advance it as it enters. {2}{W}: Advance this as a sorcery.)
Whenever Hoverstepper advances, target creature gets +1/+1 and gains flying until end of turn.

When Howler Sellout enters, for each creature that died this turn, post a bounty on up to one target creature an opponent controls. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

When Howler Sheriff enters, gain control of up to one target creature with a bounty counter on it until end of turn. Untap that creature. It gains haste until end of turn.

Destroy target Human creature.

As Humble Abode enters, choose a creature or planeswalker type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast spells of the chosen type.

{T}: Add {C}.
Ascend—Tap ten untapped permanents you control. (Tap ten untapped permanents you control: Exile this land, then return it to the battlefield transformed. Ascend only as a sorcery.)

When Humble Shepherd enters, create a 0/1 white Sheep creature token.
{T}, Tap an untapped Sheep you control: Add one mana of any color.

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
Equipped creature gets +3/+2.
Equip {2}

Enchant player
For each 1 life enchanted player would gain, you gain 1 life instead unless that player pays {1}.

Menace
Other Zombies you control get +1/+1.
Whenever a Zombie you control dies, each opponent loses 1 life.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack, add a quest counter.
Upgrade target creature you control. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Deathtouch
Target attacking creature fights up to one other target creature.
​