msem-instigator

No more than two creatures can attack each combat.

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

Hozen Shrine enters tapped.
{T}: Add {U} or {B}.
{U/B}, {T}, Sacrifice Hozen Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

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

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.

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

{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.)

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

When Hunter's Arsenal enters, create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
{1}, {T}, Sacrifice Hunter's Arsenal: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Huolin Shrine enters tapped.
{T}: Add {R} or {W}.
{R/W}, {T}, Sacrifice Huolin Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

{T}: Add {C}.
{3}{U}: Until end of turn, I's Observatory becomes a 1/4 creature. It's still a land. It has menace if {B} was spent to activate this ability, has first strike if {R} was spent, and assigns combat damage equal to its toughness rather than its power if {G} was spent.

Ice Path enters tapped.
As Ice Path enters, choose a color.
You may spend {C} as though it were mana of the chosen color.
{T}: Add {C}.

{1}, {T}: Tap target artifact, creature, or land.

{T}: Add {C}.
{2}: Idravir becomes a 2/2 creature with undying in addition to its other types until end of turn. (When that creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Idyllic Oasis enters tapped unless you control a Plains.
{T}: Add {G} or {U}.

As long as it's your turn, equipped creature has first strike and deathtouch.
If equipped creature would deal damage to a player or planeswalker, it deals four times that damage to that player or planeswalker instead.
Equip {4}

When Illustrious Lantern enters, put a +1/+1 counter on target creature you control.
{4}, {T}: Put a +1/+1 counter on target creature you control.

Immolated Grave enters tapped.
{T}: Add {R}.
{2/R}{2/R}: Immolated Grave becomes a 3/1 red Elemental creature with first strike until end of turn. It's still a land.

When Imperfect Stone enters, mill three cards.
{T}: Add one mana of any color.

As Imperial Barracks enters, you may reveal a Mountain or Plains card from your hand. If you don't, Imperial Barracks enters tapped.
{T}: Add {R} or {W}.

{T}: Add {C}.
{4}, {T}, Put a -1/-1 counter on a creature you control: Draw a card.

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}: Add one mana of any color. When you do, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Equipped creature gets +3/+2.
Equip {3}

Imperial Marketplace enters with a charge counter on it.
{T}: Add {C}.
{T}, Remove a charge counter from Imperial Marketplace: Put a +1/+1 counter on target creature you control.

{T}: Add {C}. Activate only if you have less life and control fewer creatures than each opponent.