msem-instigator

When Defiant Bristles dies, put a +1/+1 counter on target creature.

When Defiler of Farmsteads enters, each opponent loses 2 life and you gain 2 life.

Creatures with power greater than Deformed Vagrant's power can't block it.

Deft Goldsnatch can't be blocked.

Flying

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.

Whenever you scry, tap target creature an opponent controls.
{2}{W}{U}: Scry 1. You gain 1 life.

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.

Flying
When Delivery Bird enters, if you control an artifact, put a +1/+1 counter on another creature you control.

Whenever Deluge Crab perseveres, target opponent mills three cards. (A creature perseveres when it survives damage.)

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.)

Creatures you don't control get -1/-0 as long as their controller is cursed.

When Delugic Surger enters, if you control another Elemental, return target instant or sorcery card from your graveyard to your hand.

Delusional Noble enters with a -1/-1 counter on it.

When Delusive Shadows enters, each opponent loses life equal to the number of cards that player owns in exile.

(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.

At the beginning of your upkeep, choose a creature. Its controller may sacrifice it. If that player doesn't, you gain life equal to its power.

At the beginning of each player's end step, that player sacrifices a permanent.

Whenever an opponent casts a spell, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Spells your opponents cast cost an additional 2 life to cast until your next turn.

When Demented Brainiac enters and at the beginning of your upkeep, each opponent mills two cards.
{U}, Sacrifice Demented Brainiac: Exile each opponent's graveyard. Until end of turn, you may cast instant and sorcery spells exiled this way, and you may spend mana as though it were mana of any color to cast them.