msem-instigator

{2}: Duela Duelist gains first strike until end of turn.
{3}: Duela Duelist gains distorted until end of turn. (This creature can be blocked by tapped creatures but not untapped creatures.)

Whenever you cast an instant or sorcery spell, you may untap Duela Science Kit.
{T}, Tap an untapped creature you control: Catalyze. (The next spell you cast this turn costs {1} less to cast.)

Equipped creature gets +1/+0 and has first strike.
As long as another artifact named Dueling Blades is attached to a creature you control, equipped creature has double strike.
Equip {1}

Equipped creature gets +1/+1.
Equipped creature can't be blocked by more than one creature.
Equip {1}

{3}{R}: Target creature can't be blocked this turn if it's an artifact creature or has power 2 or less.

Enchant creature
Enchanted creature gets +2/+2 and can't be blocked as long as defending player controls a Desert.

Reach (This creature can block creatures with flying.)

Assault {1}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Dune Tromper assaults, it gains trample until end of turn.

When Dunecrest Pariah enters, you may search your library for a basic land or Desert card, reveal it, put it into your hand, then shuffle.
{T}, Sacrifice Dunecrest Pariah: You may put a land card from your hand onto the battlefield tapped.

Dunesea Expanse enters tapped unless you control another Desert.
{T}: Add {W} or {U}.

Reach
{T}: Add one mana of any color. Spend this mana only to cast an Azra or Demon spell, and that spell can't be countered.

Vigilance, ward {2}
{1}{G}, {T}: Put a +1/+1 counter on Dunetreader Tortoise. Activate only as a sorcery.

Protection from Dawn Chord (This creature can't be blocked, targeted, dealt damage, or enchanted by anything named Dawn Chord.)
{1}{R}: Target Reflection's base power becomes equal to Dusk Chord's power until end of turn.

Landfall — Whenever a land you control enters, target creature you control gains vigilance until end of turn.

Each other nontoken Elf and/or Warrior you control enters with an additional +1/+1 counter on it.
{G}{G}, {T}, Remove two +1/+1 counters from among creatures you control: Create two 1/1 green Elf Warrior creature tokens.

({T}: Add {B} or {G}.)
Duskwood Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Landfall — Whenever a land you control enters, Duskwood Vanguard gets +1/+1 until end of turn.

Landfall — Whenever a land you control enters, you may pay {1}{G}. If you do, create a 2/2 green Wolf creature token.

{T}: Add {C}.
{T}: Target player exiles a nonland card from their graveyard.

Dustchoked Outpost enters tapped.
When Dustchoked Outpost enters, create a 1/1 Scout creature token that's all colors. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.
{T}: Add {R}.

{T}: Add {C}.
{1}, {T}: Target player exiles a card from their graveyard. If a creature or planeswalker card is exiled this way, create a Vessel token. (It's an enchantment with “{2}, Sacrifice this enchantment: Create a 1/1 white Spirit creature token with flying.”)

{T}: Target player mills a card.
{4}, {T}, Exile Dusty Record: Target player shuffles their graveyard into their library.

When Dutiful Camel enters, put a +1/+1 counter on target creature you control.

Reach