msem-instigator

Choose a creature type. Reveal cards from the top of your library until you reveal a card of the chosen type. Put that card into your hand and the rest on the bottom of your library in a random order.

Choose one or both —
• Put a +1/+1 counter on each creature you control.
• Attacking creatures you control gain lifelink and indestructible until end of turn.

Target creature gets +X/+X and gains trample until end of turn.
If you've sacrificed a permanent this turn, draw a card.

Flying
Creatures your opponents control get -1/-0.

Trample
Spells your opponents cast that target creatures you control cost {2} more to cast.
Whenever a creature you control attacks alone, it gets +2/+2 until end of turn.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Untap each Horror you control during enchanted creature's controller's untap step.

At the beginning of combat on your turn, create a 1/1 green Elf creature token. That token gains haste until end of turn and attacks this combat if able.
At the beginning of your postcombat main phase, if three or more creatures you control dealt combat damage to a player or planeswalker this turn, add three mana of any one color.

Gloomtide Gulf enters the battlefield tapped.
{T}: Add {U} or {B}.
{1}, {T}: Add one mana of any color.

Whenever a creature enters the battlefield under an opponent's control, you may pay 2 life. If you do, draw a card.

Whenever equipped creature attacks, exile target nonland permanent until Grab Bag leaves the battlefield.
Whenever equipped creature deals combat damage to a player, put a card exiled with Grab Bag onto the battlefield under your control.
Equip {3}

Greenheart Den enters the battlefield tapped.
{T}: Add {G}.
{G}, {T}: Target creature you control gets +1/+1 until end of turn. Activate only as a sorcery and only if you control a green creature.

Whenever another Hound enters the battlefield under your control, put a +1/+1 counter on Greypelt Initiate.

Enchant opponent
When Grisly Hunger enters the battlefield, enchanted player's life total becomes 10.
At the beginning of enchanted player's end step, they sacrifice a creature. If they do, they lose life equal to that creature's power.

Untap up to two permanents you control during each other player's untap step.

Flying
As long as you control an equipped creature, Guide of Heroes gets +1/+1 and has first strike.
As long as you control an enchanted creature, Guide of Heroes gets +1/+1 and has vigilance.

Flash
Flying
Whenever H13 Wasp enters or you cast an another spell with flash or an instant, exile up to one target nonland permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

[+1]: Haide Bankbuster deals 2 damage divided as you choose among one or two targets.
[+1]: Draw two cards unless any player has Haide Bankbuster deal 3 damage to them.
[–9]: Until end of turn, gain control of all permanents target player controls and they gain haste. Untap those permanents.

Survivors you control have vigilance.

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.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)
Whenever Haploc Blooddrinker becomes blocked, it gains lifelink until end of turn.

Cast this spell only during your turn and only during the declare attackers step or with its acquiesce ability.
Untap all creatures you control. After this phase, there is an additional combat phase.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Haughty Chateau enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

At the beginning of each player's upkeep, sacrifice Hayuan, the Misjudged if that player controls a creature with power 2 or less.
When Hayuan dies, create X Idol tokens, where X is the number of creatures you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Hazy Summits enters the battlefield tapped.
{T}: Add {R} or {W}.
{1}, {T}: Add one mana of any color.

Creature spells you cast cost {1} less to cast.