msem-instigator

Flying
When Depraved Imp enters the battlefield, if you control a legendary creature, put two +1/+1 counters on Depraved Imp.

{B}, Sacrifice another creature: Deranged Apothecary gains indestructible until end of turn.

As an additional cost to cast this spell, sacrifice a creature.
Create a 5/5 black Demon creature token with flying. You lose 2 life.

Destroy each artifact with mana value X or less, then create an Idol token for each artifact destroyed this way. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Target opponent loses 1 life for each creature they control. You gain 2 life for each Wizard you control.

Target creature gets -2/-2 until end of turn.
Dominance — That creature gets -4/-4 until end of turn instead if you control the creature with the greatest power or tied for the greatest power.

When Diao, Dragoon Captain enters the battlefield, create three 1/1 red and white Warrior creature tokens.
Whenever a creature you control attacks, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

Put target creature into its owner's library third from the top.

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
Fabled {3}{R}{R} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

When Diseased Prophet enters the battlefield, each opponent loses 1 life.
Revive {B} ({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.)

Cast this spell only if each graveyard has a creature card in it.
Each player puts a creature card in their graveyard of an opponent's choice onto the battlefield.

Whenever Dissenting Vikings attacks, if you control another Warrior, it gets +1/+0 until end of turn and deals 1 damage to defending player.

Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.
Metamorph {2}{U} (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.)

Flying, first strike, haste
Whenever Doombringer Dragon attacks, you may sacrifice another creature. If you do, Doombringer Dragon gets +3/+0 until end of turn.

{R}: Draconic Aspirant gets +1/-1 until end of turn.

Equipped creature gets +0/+4 and has vigilance and reach.
Equip {3}

Ferocious — If you control a creature with power 4 or greater, you may cast Dragon Grip as though it had flash. (You may cast it any time you could cast an instant.)
Enchant creature
Enchanted creature gets +2/+0 and has first strike.

Defender, flying
Whenever you cast a noncreature spell, Dragon Initiate gets +2/+0 and loses defender until end of turn.

Dragon Queen's Den enters the battlefield tapped.
{T}: Add {U}.
{U}, {T}: Scry 1. Activate only as a sorcery and only if you control a blue creature.

Haste
Dominance — {T}: Create a 5/5 red Dragon creature token with flying. Activate only if you control the creature with the greatest power or tied for the greatest power.

Draw two cards.
Dominance — Draw three cards instead if you control the creature with the greatest power or tied for the greatest power.

Dominance — When Dragon Queen's Pupil enters the battlefield, put a +1/+1 counter on it if you control the creature with the greatest power or tied for the greatest power.

Menace
Whenever Dragon's Twisted Shadow attacks and isn't blocked, it gets +4/+0 until end of turn.

{2}: Dragonfire Longboat gets +1/+0 until end of turn.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Double strike
{3}{R}{W}: Create Hao'Tai's Blessing, a legendary red and white Aura enchantment token with enchant creature and “Enchanted creature gets +3/+3 and has flying” and attach it to Duan, the Fabled Rider.