msem-instigator

When Ethereal Spellmaster enters, if it was cast, you may search your library for an instant or sorcery card with mana value 3 or less and cast it without paying its mana cost. If you do, shuffle your library. (If it has X in its mana cost, X is 0.)

First strike
Whenever Silverblade Cathar and at least two other creatures attack, draw a card.

Drakon Nightshade can't block.
When Drakon Nightshade dies, scry 1.

{T}: Add {C}.
{T}: Put a +1/+1 counter on each legendary creature and a loyalty counter on each planeswalker that you control entered this turn.

(Add a quest counter as this enters. Sacrifice after 3.)
Once each turn, when a player discards a card, you may add a quest counter.
1, 2 — Each opponent loses X life and you gain X life, where X is the number of quest counters on Gloomhollow Expedition.
3 — Choose up to two target creature cards in graveyards with total mana value 3 or less. Put those cards onto the battlefield under your control.

As Stained Reliquary enters, choose a card type.
{T}: Target player exiles a card from their graveyard of the chosen type.
{2}, Exile Stained Reliquary: Exile all graveyards. Create a tapped 1/1 white Spirit creature token with flying.

Menace, haste

Haste
Whenever Herald of the Humble deals combat damage to a player, that player reveals the top card of their library. If it's a nonland card with mana value 3 or less, they may cast it without paying its mana cost.

When Peeto enters, scry 2.
Whenever a Scout you control attacks, choose land or nonland, then look at the top card of your library. If it's a card of the chosen kind, you may reveal it and draw a card.

Enchant creature
Enchanted creature gets +2/+2 as long as it's legendary. Otherwise, it can't attack or block.
When enchanted creature dies, if it's legendary, return that card to its owner's hand.

This spell costs {1} less to cast for each Satrapy you control.
Vigilance, menace
When Zhubin, Spear of Kaneh enters, create three 1/1 white Soldier creature tokens. Then you gain 1 life for each other creature you control.

You may have Strikebreaker enter as a copy of a non-Aura enchantment you control, except it's a 2/2 Construct Actor creature in addition to its types.

Exile all creatures. Exile Cycle of Creation with X genesis counters on it, where X is the number of creatures exiled this way.
Whenever you cast a spell, if Cycle of Creation is in exile, you may remove a genesis counter from it. If you do, create a 1/1 white Human creature token.

This spell costs {2} less to cast if there's a storied card in your graveyard. (Enchantments and legendary cards are storied.)
Search your library for a storied card, reveal it, put it into your hand, then shuffle.

Concord — Silt-Trench Brute gets +3/+3 and has trample as long as there are four or more card types among permanents you control.

When Primordial Progenitor dies, create two 1/1 red Elemental creature tokens.

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, Artisan of Brutality gets +2/+0 and gains first strike until end of turn.

Each other Okus planeswalker you control enters with two additional loyalty counters on it.
[–2]: Draw two cards, then discard a card.

Menace
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Whenever a player activates an ability that isn't a mana ability, Burning-Tree Shaman deals 1 damage to that player.

Equipped creature gets +2/+0 and has “{T}, Unattach Javelin: It deals 2 damage to target creature.”
Equip {2}

Each player sacrifices a creature and discards a card.
Fuse (You may cast one or both halves of this card from your hand.)

Flash
When Wiretapper enters, choose one —
• Exile target spell. For as long as that card remains exiled, its owner may play it. A spell cast this way costs {2} more to cast.
• Create a copy of the card with target spell's name. You may cast the copy. (You still pay its costs.)

Clutch Shot deals 2 damage to target creature or planeswalker. If you control six or more lands, Clutch Shot deals 4 damage instead.

Other attacking Foxes you control get +1/+0.
{2}{R}, Sacrifice Jiu: Discard your hand, then draw a card for each tapped Fox you control.