msem-instigator

({T}: Add {R} or {G}.)
As Dangerous Territory enters, you may pay {1}. If you don't, Dangerous Territory enters tapped.

When Darna's Grimoire enters, you may discard a card. If you do, draw a card.
{2}, Sacrifice Darna's Grimoire: Draw a card.

Draw a card.

When Datalith enters, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
{T}: Add one mana of any color.

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

Dawn Hill Outskirts enters tapped unless you played it from exile.
{T}: Add {R} or {W}.

At the beginning of combat on your turn, choose one —
• Equipped creature gets +2/+0 and gains first strike until end of turn.
• Equipped creature gets +0/+2 and gains vigilance until end of turn.
Equip {3}

Dawnlit Battlefield enters tapped.
{T}: Add {R} or {W}.
{2}{R}{W}: Until end of turn, Dawnlit Battlefield becomes a 4/2 red and white Warrior creature with with “This creature has first strike as long as it's attacking” 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.)

Haste
Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Spend only mana produced by artifacts to cast Dawson's Jetslicer.

When Dawson's Loot enters, mill two cards, then draw a card.
{1}, {T}, Sacrifice Dawson's Loot: Add one mana of any color.

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.

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.)

{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}.

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

When Dedicated Waypoint enters, create a 1/1 white Scout creature token.
{T}: Add {R}, {W}, or {B}.

Deepdrinker's Domain enters tapped.
{T}: Add {U}.

At the beginning of your upkeep, choose an opponent. That player creates a 3/2 colorless Horror creature token.
{2}: Target opponent gains control of Deepdrinker's Effigy.

Deeplife Cavern enters tapped unless you control a Forest.
{T}: Add {U} or {B}.

{T}: Add {C}.
{3}{R}: Until end of turn, Defect's Precinct becomes a 3/3 creature. It's still a land. It has trample if {G} was spent to activate this ability, has vigilance if {W} was spent, and has hexproof if {U} was spent.

Whenever you cast a spell, if it shared a color with the last spell you cast this turn, put two +1/+1 counters on Defected Android.

Flying

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