msem-instigator

Flying, lifelink
When Daystrider Pegasus enters, exile another target non-Pegasus permanent you control, then return it to the battlefield under its owner's control.

When Dazzling Festivities enters or at the beginning of your upkeep, you may have each player reveal the top card of their library. Starting with you, each player may cast a nonland card revealed this way without paying its mana cost.

At the beginning of your upkeep, you may choose a color, then exile two cards of that color from your graveyard. If you do, return a creature, instant, or sorcery card of that color from your graveyard to your hand.

{U}, Discard a card: Exile target instant or sorcery card from your graveyard. If you do, copy it. You may cast the copy.
{B}, Discard a card: Exile target creature card from your graveyard and pay its mana cost. If you do, create a token that's a copy of it. Activate only as a sorcery.

Whenever a creature you control deals combat damage to a player, it cackles. (Put a menace counter on it. If it already has menace, it deals 1 damage to each opponent instead.)
{3}{B}: Each creature you control with menace gains lifelink until end of turn.

Each creature can't have power greater than its base power and can't have toughness greater than its base toughness.

Deathtouch
When Deathbed Confessor enters, if it entered from a graveyard or you cast it from a graveyard, you draw two cards and you lose 2 life.

Enchant creature
When Deathless Conscription enters, untap enchanted creature.
You control enchanted creature.

You don't lose the game for having 0 or less life.
Whenever you're dealt damage, mill that many cards.
{B}, Pay 2 life: Put target card in your graveyard on the bottom of your library.

Enchant creature
Enchanted creature has winnow. (Damage dealt to it also causes its controller to lose that much life.)

Whenever a creature you control perseveres, you draw a card and you lose 1 life. (A creature perseveres when it's dealt damage and doesn't die.)
{1}{B}: Deathmask Initiation deals 1 damage to target creature you control.

Whenever another creature you control enters, you may change Declan, Wayward Squire's base power and toughness to that creature's power and toughness until end of turn.

Indestructible (Damage and effects that say “destroy” don't destroy this creature.)
Whenever Declare, the Mother Bear deals combat damage to a player, put a +1/+1 counter on it.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player mills a card.

As long as it's your turn, Defect 37 is a 7/7 Vehicle artifact with crew 2.
[+1]: Creatures and Vehicles you control get +1/+1 until end of turn.
[–1]: Put target permanent into its owner's library, third from the top. If Defect 37 is on the battlefield, return her to her owner's hand.
[–6]: Until end of turn, each noncreature, nonland permanent you control becomes a creature in addition to its other types with base power and toughness each equal to their mana value or base power, whichever is greater.

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.)
Whenever you draw a permanent card from the archived library, you may have Defect's Study become a copy of it until end of turn.

Flash
When Dehmi, Origin Seeker enters, counter target spell an opponent controls unless that spell's controller has you create X 1/1 red Elemental creature tokens, where X is that spell's mana value.

Enchant non-Camel creature
When Dehydrate enters, draw a card.
Enchanted creature gets -1/-0.

Dekinn, Depths Spirit can't attack or block unless a player has lost 3 or more life this turn.
At the beginning of each player's upkeep, that player may create a Mountain token. If they do, Dekinn deals 3 damage to them.
When Dekinn dies or is put into exile from the battlefield, you may put him into his owner's library third from the top.

Enchant creature
When Delegitimize enters, target opponent sacrifices a land.
Enchanted creature gets +2/+1.

Discard a land card: Target creature can't block this turn.
{R}, Discard a land card: Target creature gets +2/+0 until end of turn.

When Deliver from Dilapidation enters, you may sacrifice any number of enchantments. Whenever you sacrifice an enchantment this way, destroy target creature.
At the beginning of your upkeep, return target enchantment card with mana value 5 or less from your graveyard to the battlefield.

Creatures you control get +1/+1 for each noncreature spell you've cast this turn.
When Deliverance Branch enters, create three 1/1 white Cleric creature tokens with lifelink.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Each creature you control with a counter on it has ward {2}. (If a creature has multiple instances of ward, each triggers separately.)

(As this Saga enters and after your draw step, ad a lore counter. Sacrifice after III.)
I, II — Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
III — You may sacrifice any number of artifacts. If you do, draw that many cards.