msem-instigator

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}

Target creature gets +2/+0 until end of turn and can't be blocked except by three or more creatures this turn.
Flashback {U/R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Untapped creatures you control get +1/+1.
Soldiers you control have vigilance.

As Duke Gerard Hoff enters, an opponent gains control of it.
Duke Gerard Hoff can't attack its owner or planeswalkers that player controls.
Creatures your opponents control get +2/+1.

When Duncaster Nightwatcher enters and whenever you cast a noncreature spell, create a 1/1 colorless Human creature token.
Whenever you attack with three or more creatures, return target noncreature, nonland card with mana value 3 or less from your graveyard to your hand.

At the beginning of your upkeep, choose one —
• Create a colorless artifact token named Etherium Cell with “{T}, Sacrifice this artifact: Add one mana of any color.”
• Put a +1/+1 counter on another target artifact. It becomes a 0/0 Construct artifact creature if it isn't a creature.

Menace
Whenever a creature you control deals combat damage to a player, exile the top card of that player's library. They lose life equal to that card's mana value.

Copy target spell. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Flash
When Duplicated Dismantler enters, if you cast another spell this turn, return target spell to its owner's hand.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

When Dusk Lieutenant enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)
Once each turn, when you discard a card during your turn, each opponent discards a card.

When Duskling Stalker dies, if it didn't have any counters on it, return it to the battlefield with your choice of a deathtouch, lifelink, or +1/+1 counter on it.

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 {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.”)

Dutiful Chasqui gets +2/+1 as long as you control two or more other creatures that share a name with it.
A deck can have any number of cards named Dutiful Chasqui.

Prowess
Whenever you cast an instant or sorcery spell, if its mana value is less than or equal to Dwarven Twinslinger's power, copy that spell. You may choose new targets for the copy.

Equipped creature gets +1/+1 and has double strike.
Equip {2}{R}
Madness {2}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
When Dwarven War Hatchet enters, if you cast it for its madness cost, attach it to target creature you control.

Flying, haste
When EHSAE, Entelan Skycraft deals combat damage to a player, you may return it to its owner's hand. If you do, you may search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.
Crew 3

Eager Observer gets +1/+1 as long as you control an artifact or enchantment.

When Earthbreaker Behemoth enters, it deals damage equal to its power to up to one target creature you don't control. Excess damage is dealt to that creature's controller instead.

{T}: Add {G}.

{G}: Each player exiles a card from their graveyard. If an instant or sorcery card is exiled this way, put a +1/+1 counter on Earthfeeder Worm.
Remove X +1/+1 counters from Earthfeeder Worm and sacrifice it: Exile X target cards from graveyards.

This spell costs {1} less to cast for each noncreature, nonland permanent you don't control.
When Earthform Pachyderm enters, destroy target noncreature, nonland permanent. Its controller creates a 3/3 green Elephant creature token.

Return up to six target cards in your graveyard that don't share colors to your hand.
Exile Earthly Ambitions.

Vigilance, reach
Deploy 5 (As this enters, you may tap any number of other creatures you control with total power 5 or more.)
When Earthly Principality enters deployed, your life total becomes equal to your starting life total plus 5.