msem-instigator

Tap two untapped Elves you control: Add {G}{G}.
{6}{G}{G}: Create an 8/8 green Elemental creature token.

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.

Counter target spell if it wasn't cast from a player's hand.

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.

Destroy all creatures.
Kindle X—{X}, Exile a card with mana value X from your graveyard. ({X}, Exile a card with mana value X and this card from your graveyard: Create X 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

Dead-Set Duo can't block.
Whenever Dead-Set Duo deals combat damage to a player, you may pay {B} and sacrifice it. If you do, they discard two cards.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Deadland Summoner dies, you may put the card it engorged into your hand. If that card is an instant or sorcery card, you may instead cast it without paying its mana cost.

{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.

Deadwood Grove enters tapped.
{T}: Add {B} or {G}.
{1}{B}{G}: Until end of turn, Deadwood Grove becomes a 2/3 black and green Horror creature with with deathtouch and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Deathtouch
When Deadwood Terror enters from a graveyard, create two tokens that are copies of it.
{4}{B}{B}, Sacrifice a creature: Return Deadwood Terror from your graveyard to the battlefield. Activate only as a sorcery.

Destroy target creature that's not enchanted and isn't an enchantment.

Destroy four target creatures.

Put target permanent on top of its owner's library.

You can't cast this spell as long as your life total is greater than half your starting life total.
Lifelink
{1}{B}{G}, Discard Death's Widow: Destroy target nonland permanent. You lose life equal to its mana value.

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.

When Deathless Hunter dies, you may put it on the bottom of its owner's library.

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.

You may exert Deathmarked Explorer as it attacks. When you do, it gets +X/+X until end of turn, where X is 10 minus your life total. (An exerted creature won't untap during your next untap step.)
{T}, Discard a card: Draw a card. Deathmarked Explorer deals 2 damage to you.

Creatures you control have menace.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {W} or {B}.

Deathwind Survivor's power and toughness are each equal to the number of enchantments you control.
Whenever an enchantment you control enters, put a +1/+1 counter on target creature.

When Debaser of Truth enters, if you control three or more Horrors, each opponent discards two cards.
Other Horror creatures you control get +1/+1.

{T}: Put a flood counter on Decanter of Endless Rivers. Add {U} for each flood counter on it.

Decay deals damage to creatures in the form of -1/-1 counters.
{B}{G}: Until end of turn, target creature deals damage to creatures in the form of -1/-1 counters. Activate only if Decay is in your graveyard.

Deception can't be blocked.
{1}{U}{B}: Target creature can't be blocked this turn. Activate only if Deception is in your graveyard.