msem-instigator

First strike
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Almgrove Champion can only attack or block alone.

{2}{G}: Exile up to three cards from graveyards. Autocrat X, where X is the number of cards exiled this way. (If you don't control an autocrat, put X +1/+1 counters on this. It becomes an autocrat until it has no +1/+1 counters on it.)
Whenever Hegemony Monarch attacks, you may exile target card from a graveyard. If you do, untap it and it gains trample until end of turn.

When Expedition Outfitter enters, create a 1/1 colorless Servo artifact creature token.
At the beginning of each end step, if an artifact was put into your graveyard from the battlefield this turn, Expedition Outfitter deals 1 damage to each opponent.

Up to three target creatures each get +1/+1 until end of turn.

{T}: Adept Fisherman voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Adept Fisherman phases in, you gain 2 life.

This spell costs {1} less to cast for each card type among cards in your graveyard.
Scavenge {4}{G}. This ability costs {1} less to activate for each card type among other cards in your graveyard. ({4}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Whenever Mortified Medium or another creature enters, you gain 1 life.
As long as you have at least 10 life more than your starting life total, Mortified Medium gets +4/+4 and has flying.

Target creature you control gets +0/+3 and gains hexproof until end of turn.

Harmony — Destroy target artifact or enchantment.
When Rejoicing Aristocrats enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
During each of your turns, you may cast an instant or sorcery spell from your graveyard. If that spell would be put into your graveyard, exile it instead.
Whenever Aurora, Soulweaver attacks, untap any number of target creatures.

Sculpted Observatory enters tapped.
{T}: Add {W} or {U}.
{1}, {T}: Add one mana of any color.

Whenever equipped creature attacks, choose one —
• Tap target creature.
• Draw a card, then discard a card.
• Exile target card from a graveyard.
Equip {3}

As an additional cost to cast this spell, discard a card.
Return target card from your graveyard to your hand.

Flying
Clerics you control are Demons in addition to their other types.
Attacking Demons you control have deathtouch.

Motivate 1 (When this creature enters, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)
When Merthilios' Escort motivates a creature, that creature gains first strike until end of turn.

Prowess
At the beginning of each end step, if you cast a multicolor spell or two spells with different colors this turn, each opponent sacrifices a permanent.

Menace
Regal Dragoon gets +1/+1 as long as you control a legendary creature.

Whenever a creature deals combat damage to you, that creature's controller gains control of Nightmare Alley.
{T}: Add {C}.
{1}, {T}: Target attacking creature gets +1/+0 until end of turn and can't be blocked this turn.

Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter.)
Duskscale Marauder can't be blocked.

Target creature gains hexproof and indestructible until end of turn. That creature seeks secrets. (Give it that Oath Aura. Fulfill it by attacking with it and two or more other creatures to draw a card.)

When Silverhorn Tactician enters, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

{T}, Sacrifice a land: Untap up to three target lands.

Trample
When Descendant of Shimaru enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

When Suspect Concoctions enters, put a +1/+1 counter on target creature.
{4}, Sacrifice Suspect Concoctions: Put two +1/+1 counters on target creature.

If a creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
[+1]: Target player draws two cards, then discards a card. Put a +1/+1 counter on up to one target creature you control.
[–3]: Create a token that's a copy of target creature you control.
[–8]: Return any number of target nonland permanents to their owner's hand.