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

Destroy target nonland permanent.
If you've sacrificed a permanent this turn, draw a card.

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

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

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.”)

Reach
When Headhunter Mantis enters, if a creature you controlled died this turn, create a 1/1 green Insect creature token.

When Heedless Lovers enters, you may return target Citizen card from your graveyard to your hand.
Persist (When this 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.)

Choose five target cards in your graveyard. An opponent separates those cards into two piles. Put one pile into your hand and exile the other. Exile Hell or High Water.

Whenever another nontoken creature you control dies, create a 1/1 green Saproling creature token.
{B}{G}, {T}, Sacrifice a creature: Return target permanent card from your graveyard to your hand.

When Hoof Cliff Caretaker enters, return target card of an opponent's choice from your graveyard to your hand.

Return up to one target permanent card and up to one target Horror card from your graveyard to your hand.

You may cast Hunter of the Moon-Serpent from your graveyard as long as you gained life this turn.

Whenever Imisti, Elven Insurgent attacks, mill two cards. When you do, you may return target land card from your graveyard to your hand.
{X}{B}{G}: If Imisti has no +1/+1 counters on it, put X +1/+1 counters on Imisti. Activate only as a sorcery.

At the beginning of your upkeep, if you control three or more creatures, you draw a card and you lose 1 life.
{2}{B}{G}: Create a tapped 1/1 Horror creature token that's all colors.

{T}: Add one mana of any color.
Whenever you tap Ingrained Virago for mana, each opponent loses 1 life.

Mill three cards, then you may return a creature or land card from your graveyard to your hand.

Codex — Little Pig; Charging Cassowary; The Lonely Hunter; Shadowlurk; Blood Constrictor. (As this enters, conjure its contents into a shuffled face-up additional library.)
You may cast Adventures of this codex's contents from your graveyard.

[+1]: Create a tapped 3/3 black Crocodile creature token with menace.
[–1]: You may cast a copy of Size Up.
[–7]: Each land you control becomes a 3/3 Crocodile creature and gains menace and haste until end of turn.

When Irreverent Sinscape enters, destroy up to one other target nonland permanent.
When Irreverent Sinscape dies, exile it. When you do, you may exile any number of cards from your graveyard that have four or more card types among them. If you do, return a permanent card from a graveyard to the battlefield under your control. You may repeat this process any number of times.

Sacrifice two lands, Mill five cards: Return Jack, Horrific Harvester from your graveyard to your hand.
[+1]: You gain 2 life and each opponent loses 2 life.
[–2]: Return up to one target creature card and up to one target land card from your graveyard to your hand.
[–2]: Each opponent sacrifices the nonland permanent they control with the greatest mana value among permanents they control.

Jara Favored gets +2/+2 as long as you've lost life this turn.

Destroy target permanent. Trigger a death knell of any number of permanents you control.

Vigilance, haste
All creatures able to block Jormir, Who Encircles All do so.
Jormir, Who Encircles All can block any number of creatures.

Jungle Hollow enters tapped.
When Jungle Hollow enters, you gain 1 life.
{T}: Add {B} or {G}.