msem-instigator

Target instant or sorcery card in your graveyard gains flashback until end of turn. Its flashback cost is equal to its mana cost reduced by {2}.
Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Target creature gets +2/+2 and gains first strike until end of turn.
Metamorph {R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

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

Dazzling Duelist has first strike as long as it's attacking.
{2}{R}: Dazzling Duelist gets +2/+0 until end of turn.

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.

Up to two target creatures can't block this turn.
Draw a card.

Equipped creature gets +4/+2.
Equip—Sacrifice a creature. (Sacrifice a creature: Attach to target creature you control. Equip only as a sorcery.)

Dead Man's Hand enters tapped.
{T}, Sacrifice Dead Man's Hand, two permanents with mana value 1, and two permanents with mana value 8: Target player loses the game.

Primal {R} (During your turn, you may cast this spell for {R} instead of playing a land.)
When Deadeye Drowner enters, it deals 2 damage to any target.

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.)

Engage (This creature must be blocked each combat if able.)
Whenever Death Pits Gladiator perseveres, profit. (A creature perseveres when it survives damage. To profit, create a colorless Gold artifact token with “Sacrifice this artifact: Add one mana of any color.”)

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.”

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.

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

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.

{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.”

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

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

Decayed Bedchamber enters tapped.
When Decayed Bedchamber enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {B} or {G}.

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

Creatures you control get +2/+2 and gain vigilance and trample until end of turn.

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.

{T}, Sacrifice Decrepit Crags: Search your library for a Swamp or Mountain card and put it onto the battlefield tapped, then shuffle.