msem-instigator

When Dark Ascension enters, if you cast it, all creatures get -13/-13 until end of turn.
Whenever you cast a black spell, Dark Ascension deals X damage to any target and you gain X life, where X is the number of black mana symbols in that spell's mana cost.

Return target creature card from your graveyard to the battlefield. Then if you control a creature with toughness 4 or greater, create a 1/1 black Bat creature token with flying and “This creature can't block.”

When Dawnhart Ceremony enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Invocation — When you spend four or more mana to cast a spell or activate an ability during your turn, transform Dawnhart Ceremony.

{T}: Add one mana of any color.
Invocation — Whenever you spend four or more mana to cast a spell or activate an ability during your turn, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dawnhart Scourge can't be blocked by more than one creature.

Lifelink
Players casting spells and creatures entering don't cause abilities to trigger.

Vigilance
Whenever one or more cards leave your graveyard, surveil 1.

Return target creature card from your graveyard to the battlefield. If this spell was cast from a graveyard, you lose life equal to that creature's mana value.
Flashback {1}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Enchant land
When Death in Bloom enters, mill four cards, then return a permanent card from your graveyard to your hand.
Enchanted land has “{T}: Add two mana of any one color.”

Menace, haste
Invocation — Whenever you spend four or more mana to cast a spell or activate an ability during your turn, return Deathless Butcher from your graveyard to your hand.

Menace
When a card leaves your graveyard, exile the top card of your library. You may play that card until the end of your next turn.

First strike
Whenever a card leaves your graveyard, you may pay {2}{R}. If you do, this creature deals 2 damage to any target.

When this creature enters, you may sacrifice a creature. If you do, create a 4/4 red Horror creature token with menace.

When this creature enters or leaves the battlefield, create a tapped 2/2 black Zombie creature token.

When this creature enters, you may return another target creature you control to its owner's hand. If you do, create a Treasure token.

Defender
When Demonrune Wall enters, exile target creature or enchantment an opponent controls until Demonrune Wall leaves the battlefield.

Flying
When Departed Butler enters, draw a card.

Whenever this creature attacks, if you gained or lost life this turn, it gains flying until end of turn.
When this creature dies, create a 2/2 black Zombie creature token.

When Desperate Botanist enters, create a 0/1 green Plant creature token with “{T}: Add {G}.”
{5}{G}: Transform Desperate Botanist. Activate only if it's attacking.

As long as this creature isn't a Zombie, it and other Knights and Soldiers you control get +1/+1 and have vigilance. Otherwise, it and other Zombies you control get +1/+1 and have menace.
Arise {1}{W}{B} ({1}{W}{B}, Exile this from your graveyard as a sorcery: Create a black token copy of it that's also a Zombie and can't block.)

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Search your library for up to two Forest cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Flying
Whenever another creature dies, each opponent loses 1 life and you gain 1 life.

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Create an X/X green and blue Dryad creature token with ward {2}.

Flying, vigilance
{2}{G}: Return target creature you control to its owner's hand. If you do, this creature gets +2/+2 and gains trample until end of turn.

If an effect you control other than a siphon ability would put a counter on a permanent, you may put a flying, vigilance, or stun counter on that permanent instead.