msem-instigator

You gain life equal to the number of creatures you control.
Each opponent loses life equal to the number of creatures they control.
Destroy all creatures, then exile all graveyards.

Flash
Flying
When Sunset Herald enters, if it was cast, return to the battlefield all creature cards from your graveyard that were put there from the battlefield this turn.

You may have Surging Wurm assign its combat damage as though it weren't blocked.
Surging Wurm gets +2/+2 as long as seven or more cards are in your graveyard.

Choose up to one nonland permanent. Return the rest to their owners' hands.

At the beginning of your end step, put a flood counter on Swelling Sea, then return each nonland permanent with mana value less than or equal to the number of flood counters on Swelling Sea to its owner's hand.

Flying
When Syrina's Brood enters, look at the top six cards of your library, then put them back in any order.

Flying
When Syrina, the Dragon Queen enters, gain control of target nonland permanent for as long as you control Syrina, the Dragon Queen.
{2}{U}: Exile Syrina, the Dragon Queen. Return her to the battlefield at the beginning of the next end step.

Colossal 3—{7}{R}{R} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {7}{R}{R} as a sorcery: Put three +1/+1 counters on it if it has none.)
Flying
Each creature you control with a counter on it has double strike.

Hexproof

Bleed {2}{R} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
Destroy target land.

Flash
When Tenvilu, Earthen Warden enters, other creatures you control get +2/+2 and gain hexproof and indestructible until end of turn.

This spell costs {1} less to cast for each creature you control that's in a pack. (Two or more creatures you control with equal power are in a pack.)

Protection from nonblue
Whenever Terror of Palta Gorge attacks, exile another target nonblue creature until Terror of Palta Gorge leaves the battlefield.

Vigilance
When Terror of the Ulvenwald enters, target creature gets +3/+3 until end of turn.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Flying
Other Vampire creatures you control get +1/+0 and have menace.

{5}{U}{U}: Thassa's Tidebringer can't be blocked this turn. This ability costs {1} less to activate for each creature you control with a counter on it.

Menace
When The Anguilahydra enters, draw X cards and put X +1/+1 counters on The Anguilahydra, where X is the number of enchantments you control.

Whenever a creature an opponent controls dies, its controller loses 1 life.
At the beginning of each opponent's upkeep, put a -1/-1 counter on each creature that player controls.

Whenever The First Idol attacks, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Sacrifice three Idols: Return The First Idol from your graveyard your hand.

[+1]: Return target nonland permanent to its owner's hand. That player loses 2 life.
[0]: Create a 1/1 blue Bird creature token with flying for each loyalty counter on The Flock.
[–6]: You get an emblem with “If a permanent you don't control would leave the battlefield, you may instead exile it, then return that card to the battlefield under your control. It's a 1/1 blue Bird creature with flying.”

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
As long as your main library has ten or fewer cards in it, you may cast spells without paying their mana costs.

Trample
Whenever a creature you don't control dies, you gain 2 life.
Whenever you gain life, put that many +1/+1 counters on target creature you control.

Vanguard — Whenever a creature you control attacks alone, gain control of target nonland permanent for as long as you control The Rocket Gang Strikes!.

Once each turn, when another permanent you control enters, you may create a token that's a copy of that permanent, except it has no mana cost.

For each legendary permanent you control, this spell costs one mana of one of that permanent's colors less to cast. This effect reduces only the amount of colored mana you pay.
For each color, create a token that's a copy of a different legendary permanent you control of that color, except the token isn't legendary.
Exile The Tale of Kings.