msem-instigator

Remove all counters from all permanents and exile all tokens.

Enchant creature
Enchanted creature gets +2/+0 and has trample.

Once each turn, when you search your library, you may add {B}{B}.

All creatures that aren't embattled get -5/-5 until end of turn. If a creature would die this turn, exile it instead. (A creature is embattled if it has a counter on it or a permanent its owner controls attached to it.)

Adorned — As long as Voyaging Devout is equipped and/or enchanted, creatures with power less than its power can't block it.

You may put a Dragon creature card from your hand onto the battlefield. That creature gains haste until end of turn. Return it to its owner's hand at the beginning of the next end step.

Whenever another creature named Reminiscing Youth you control enters, you may discard a card. If you do, draw a card.

When Hunter's Arsenal enters, create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
{1}, {T}, Sacrifice Hunter's Arsenal: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Equipped creature has menace.
Whenever equipped creature attacks, it gets +X/-X until end of turn, where X is a number of your choice less than its toughness.
Equip {2}

Return target creature card from your graveyard to your hand. Add {G}{G}{G}. Spend this mana only to cast creature spells.

When Postmortem Contemplation enters, draw a card.
{1}{U}: Draw a card, then discard a card.

When Opulent Proprietor enters, you may search your library and/or graveyard for an Aura, Aurashaper, Equipment, or Vehicle card, reveal it, and put it into your hand. If you search your library this way, shuffle.

Flash
When Nurse Trainee enters, you may prevent the next 2 damage that would be dealt to another target creature this turn.

As Hexplate Companion enters, choose a card name.
You and Hexplate Companion each have protection from the chosen card name.

Whenever equipped creature attacks, put a charge counter on Shimmersting, then create a token that's a copy of equipped creature and that's tapped and attacking for each charge counter on Shimmersting, except the tokens aren't legendary. Exile the tokens at the beginning of the end step.
Equip {5}

Enchant player
Whenever enchanted player casts a spell from anywhere other than exile, exile that spell. During that player's next turn, they may cast that card without paying its mana cost.

Flying
Whenever a creature enters under an opponent's control, you may pay {1}{B}. If you do, fateseal 1. (Look at the top one cards of an opponent's library, then put any number on the bottom and the rest on top in any order.)

Lifelink
At the beginning of your end step, if you gained life this turn, put a +1/+1 counter on Backstage Manager.

Trample
When Leech-Encrusted Div enters, judge each creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

Create a 1/1 white Spirit creature token with flying.
Whenever a nontoken creature you control dies, you may pay {W} and exile Whispered Wishes from your graveyard. If you do, create a 1/1 white Spirit creature token with flying.

When Desert Bloom enters, you gain 4 life.
At the beginning of your upkeep, add {G}{G}.

Vigilance
{1}{W}: Jhessian Cavalier gains lifelink until end of turn.

Create a 1/1 colorless Construct artifact creature token. For each other card named Competing Design in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”

Return target creature card from your graveyard to the battlefield.
Reconstruct {4}{B}{B}{B} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Whenever you cast a black spell, you may exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.
Whenever you cast a red spell, you may have Haunted Sunseeker deal 1 damage to each creature.