msem-instigator

Sacrifice a creature: Put a +1/+1 counter on Masked Assailant. It gains menace until end of turn. Activate only as a sorcery.

Masked Impersonator can't be blocked.
Art of war — At the beginning of your end step, if Masked Impersonator dealt damage to an opponent this turn, you may have it become a copy of target creature you control except it has this ability.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Masked Lancer has first strike as long as it's attacking.
Whenever Masked Lancer mentors a creature, that creature gains first strike until end of turn.

Once each turn, when you activate a nonmana ability, you may have Masked Servant get +1/+1 until end of turn.
{2}{W}: Untap target creature.

Flying
When Masked Stalker enters, target player discards a card.

Menace
Whenever Masoh enters or attacks, each opponent that has more than four cards in hand discards cards equal to the difference. Then if you have fewer than four cards in hand, draw cards equal to the difference.

Whenever one or more cards are put into exile from anywhere, target opponent loses 1 life.
Whenever one or more creatures you control deal combat damage to a player, you may pay 2 life. If you do, purge. (Exile two cards that share a type from graveyards. If you do, draw a card.)

Whenever another creature enters, Masquerading Bohemian becomes a copy of that creature except it's a Noble in addition to its other types and it has this ability.

Create two tokens that are copies of target creature you control, except the tokens aren't legendary if the creature is legendary. Those creatures gain haste until end of turn.

Destroy all creatures. For each creature destroyed this way, its controller draws a card.

Whenever a permanent you control leaves the battlefield, discard a card, then draw a card.
{1}{R}, Sacrifice a permanent: Mass Pandemonium deals 1 damage to any target.

Whenever equipped creature attacks, it gets +1/+0 until end of turn for each other attacking creature.
Tap two untapped creatures you control: Equipped creature gains trample until end of turn.
Equip {3}

Flash
When Master Echomage enters, you may cast target instant or sorcery card from your graveyard with mana value X or less without paying its mana cost, where X is the number of Wizards you control. Exile that card instead of putting it into your graveyard as it resolves.

Flying
Whenever you cast an instant or sorcery spell from your hand, you may cast an instant or sorcery card with mana value less than or equal to that spell's mana value from your graveyard without paying its mana cost. Exile that card instead of putting it into your graveyard as it resolves.

Whenever an Actor you control becomes untapped, you may discard a card. If you do, draw a card.

Other creatures you control get +0/+1.

Flash
When Master of Disorientation enters, you may choose new targets for target instant or sorcery spell. Then proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Whenever a nonbasic nontoken land enters under an opponent's control, create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

As long as you control an Island, you may cast this spell as a copy of any creature on the battlefield. (This includes casting cost.)

You may choose not to untap Master of Minds during your untap step.
{T}: Gain control of target creature with mana value X or less for as long as Master of Minds remains tapped, where X is the number of Islands you control.

You can't cast more than one spell each turn.
Whenever you cast a spell, draw a card.

Whenever an artifact you control enters, Master of Munitions deals 1 damage to each opponent.

Trample
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever a creature an opponent controls blocks, Master of No Quarter deals 2 damage to that creature.