msem-instigator

{T}: Add {C}.
{1}, {T}, Sacrifice Perilous Passage: Destroy target nonbasic land. Activate only if an opponent controls four or more lands.

Each opponent sacrifices a creature. Whenever one or more players lose life this turn, repeat that process.

Whenever a player casts a spell from their hand, that player exiles it. Then they cast a copy of a card exiled with Embrace the Unpredictable chosen at random without paying its mana cost.

Whenever another creature you control dies, each other player sacrifices a creature.

Bloodcrazed Acolyte enters with a +1/+1 counter on it for each player who lost life this turn.

Flash
When Ancestral Warlord enters, it deals 1 damage to each blocking creature.

When Weary Adventurer enters, return a permanent you control to its owner's hand.

Destroy target creature. You gain 1 life for each card in its controller's graveyard.

{T}, Pay 1 life: Add {B} or {R}.
{2}, {T}, Sacrifice Industrial District and another permanent: Draw a card. Activate only during your turn.

Foretell {3}{G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
This spell's foretell cost costs {3} less to pay if an opponent drew two or more cards this turn.
Create a 5/5 green Beast creature token with trample.

{1}, {T}, Move a -1/-1 counter from another creature onto Dockside Healer: You gain 2 life.

When Primordial Gorran enters, if {B} was spent to cast it, put a +1/+1 counter on it for each creature card in your graveyard.

Flying
When Rahstahde Persecutor enters, you may pay {2}{R}. When you do, it deals 4 damage to target creature.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] You gain 1 life.
[Lore III] Target creature you control gains first strike until end of turn.

When Glimpse in the Static enters, exile target creature an opponent controls until Glimpse in the Static leaves the battlefield.
At the beginning of your upkeep, target player creates a token that's a copy of the exiled card, then exiles that token.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
At the beginning of each upkeep, exile the top card of the archived library and your main library. You may cast those cards this turn and may spend mana as though it were mana of any color to cast them.

When Caustic Lurker dies, target player loses 1 life.

When Fleshwrithe Ghoul enters, each player sacrifices a creature.
Revive {4}{B} ({4}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
{W}, {T}: Lightbolt Archer deals 1 damage to target unblocked attacking creature.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Nizev Rising enters, return target instant or sorcery card from your graveyard to your hand.

Hexproof
Whenever attackers are declared, the active player may pay {2} for each creature attacking you. Then you may have Bridge Kalak become an X/X Troll creature until end of turn, where X is the number of times that player didn't pay mana this way.

{T}: Target attacking or blocking creature gets +1/+1 until end of turn.

You may have Imitator of Success enter as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

Return target creature card from your graveyard to the battlefield, then rediscover a creature card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a creature card. Otherwise, put it back or into your graveyard.)

Beckon Ox {1}{W} ({1}{W}: This enchantment permanently becomes an Ox creature in addition to its other types.)
Vigilance
Whenever a creature or another enchantment you control enters, you gain 1 life.