msem-instigator

When Death's Sentry enters, if a creature died this turn, create a 2/2 black Zombie creature token.

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.

Deathtouch
{3}{G}: Deathcoil Cobra gains indestructible until end of turn.

Whenever another creature you control dies, put a +1/+1 counter on Deathfeeder.
Sacrifice Deathfeeder: Target creature gets +X/+X until end of turn, where X is Deathfeeder's power.

Flying, deathtouch

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

When Deathless Disciple dies, if it's not a token, create a token that's a copy of it, except it has no mana cost.
Revive {6}{B} ({6}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Flying
Other Spirits you control get +1/+1.
Whenever a Spirit you control attacks, you gain 1 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.

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

As an additional cost to cast this spell, sacrifice a creature.
Draw cards equal to the sacrificed creature's power.

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.

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.

{4}, {T}, Exile Deathwind Detonator: Destroy all nonland permanents. Each player gets an emblem with “At the beginning of your upkeep, you lose 1 life.”

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.

Target creature gets -2/-2 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, return up to one target enchantment card from your graveyard to your hand.

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.

When Debt Dignitary enters, tap target nonland permanent. That permanent doesn't untap during its controller's untap step for as long as you control Debt Dignitary.

{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.

Whenever Deceitful Soul becomes blocked by one or more creatures, it gets +2/+0 until end of turn.

Primal {B}{B} (During your turn, you may cast this spell for {B}{B} instead of playing a land.)
Search your library for a card and put that card into your hand, then shuffle. Exile Deceitful Tutor.