msem-instigator

Menace
At the beginning of your end step, Mountain Tyrant deals 1 damage to each creature you don't control.

First strike
Whenever you cast an artifact or enchantment spell, put a +1/+1 counter on Ironclad Infantry.

Put target creature or planeswalker on the bottom of its owner's library. Its controller may scry 1.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Whenever enchanted creature becomes the target of a spell or ability, tap it.

Whenever Weaver of Lore attacks, you may reveal your hand. Weaver of Lore gets +2/+2 until end of turn if you reveal two or more blue cards this way.

Vigilance (Attacking doesn't cause this creature to tap.)

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, Regrets of Mortals gets +2/+0 until end of turn. You may discard a card. If you do, draw a card.

As long as Imperial Proclaimer is on the battlefield, it has all names of nonlegendary creature cards in addition to its name.

When Lie in Ambush enters, create a tapped 3/3 green Beast creature token.
When Lie in Ambush leaves the battlefield, you may have target creature you control fight target creature you don't control. (Each deals damage equal to its power to the other.)

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.

When Embodiment of Abundance enters, choose one —
• Search your library for up to X basic land cards, where X is the number of lands you control, and put them onto the battlefield tapped. Then shuffle.
• Create a 1/1 green Elf Druid creature token for each creature you control.

When Bjarndyr Mender enters, other creatures you control get +1/+1 and gain indestructible until end of turn.

You lose 2 life. Look at the top two cards of your library. You may mill two cards. Draw two cards, then mill two cards if you didn't mill before.

Menace
Whenever you cycle A Most Important Prince or it attacks, each opponent with two or more cards in hand discards a card.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

When Lich's Grimoire enters, create a 2/2 black Zombie creature token.
{2}{B}, {T}: Target opponent loses 1 life. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Flash
Flying
As long as an opponent controls more creatures than you, Arbiter of the Scales gets +2/+2 and has first strike and lifelink.

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Backstage Rooms: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

{T}: Look at the top card of your library. If it's a land card, you may reveal it and put it into your hand.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Exile target creature with power 3 or less. You gain 3 life.

Discard any number of cards, then draw that many cards plus one. When you do, return target nonland permanent card with mana value less than or equal to than the number of cards discarded this way from your graveyard to the battlefield tapped.

Concord — Whenever Bubbledome Captain attacks, if there are four or more card types among permanents you control, each other attacking creature gets +1/+1 until end of turn.

{3}, {T}: Choose a card name, then reveal a card at random from your hand. If that card has the chosen name, Cursed Scroll deals 2 damage to any target.

As an additional cost to cast this spell, discard a card.
Draw two cards and crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure. Then do it again.)

{1}{B}, Pay 2 life: Moonlight Butcher gains menace until end of turn.

First strike, trample
{2}{R}, Sacrifice a land: Corrignos' Rage gets +3/+0 until end of turn.