msem-instigator

You may play Grisly Ruins from your graveyard as long as seven or more cards are in your graveyard.
Grisly Ruins enters tapped.
{T}: Add {B} or {G}.
Cycling {1}{B}{G} ({1}{B}{G}, Discard this card: Draw a card.)

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if two or more land cards are in your graveyard.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {B} or {G}.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {R} or {G}.

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

Flying
Whenever you cast a cryptic spell, Guardian of Mysteries becomes a 4/4 Sphinx creature in addition to its other types until end of turn. (Artifacts, enchantments, and modal spells are cryptic.)
{1}, {T}: Scry 2.

Guidestone enters tapped.
{T}: Add {C}.
{2}, Sacrifice Guidestone: Draw a card.

Equipped creature gets +3/+2.
Equip {4}
Hail of Blades's equip ability costs {4} less to activate if it targets an equipped creature.

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.

{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.

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

{T}: Add {C}.
{T}, Pay 1 life: Add {B} or {G}.

Haunted Estate enters tapped unless another player controls a land that could produce {W} or {B}.
{T}: Add {W} or {B}.

{T}: Add {C}.
{T}, Reappropriate: Add {U} or {R}. (Exile exactly two cards from your hand and/or graveyard.)

Haunted Hovel enters tapped.
{T}: Add {W} or {B}.
When Haunted Hovel enters, you may put a loyalty counter on a planeswalker you control.

{T}, Pay 1 life: Add {W} or {U}.
{2}, {T}, Sacrifice Haunted Manor and another permanent: Draw a card. Activate only during your turn.

Haunted Woodlock enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Hazy Coppice enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Hazy Coppice becomes a 4/4 blue and black Bird creature with with flying and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

{T}, Sacrifice Hazy Lagoon: Search your library for a Plains or Island card and put it onto the battlefield tapped, then shuffle.

({T}: Add {U} or {B}.)
Hazy Moorland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

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

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.