msem-instigator

Target creature you control deals damage equal to its power to target player or planeswalker.
Inscribe {4}{R}{G} ({4}{R}{G}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Return an artifact card from your graveyard to your hand. If you can't, you gain 2 life. Repeat this process for battle, creature, enchantment, land, and planeswalker.
Put Variety of Goods on the bottom of its owner's library.

Double strike, menace, trample
At the beginning of your end step, sacrifice Juddering Mishap unless you've cast a spell with no creature types this turn. (Noncreature spells have no creature types.)

Each creature you control assigns combat damage equal to its toughness rather than its power.
Whenever another creature you control enters, creatures you control get +0/+1 until end of turn.

At the beginning of your declare attackers step, create a 0/1 white Cat creature token that's tapped and attacking. Exile that token at the beginning of the next end step.

{1}, {T}, Pay 1 life: Put a +1/+1 counter on target creature you control.
{T}, Remove a counter from a permanent you control: Draw a card.

Create a tapped Plains token, Island token, Swamp token, Mountain token, or Forest token.

Destroy target creature or planeswalker with mana value 2 or less. Create a tapped Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

The second spell you cast each turn costs {2} less to cast.
Whenever you cast a spell, each opponent loses 1 life and you gain 1 life.

Menace, trample, indestructible
Whenever Aghavaan Unleashed deals combat damage to a player, that player gets that many poison counters.
At the beginning of your end step, sacrifice another creature or transform Aghavaan Unleashed.

Reveal the top three cards of your library and put them into your hand. If this spell was cast from your graveyard, each opponent loses life equal to the total mana value of those cards. Otherwise, you lose that much life.
Flashback {4}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

[+1]: Create a 1/1 blue Bird creature token with flying and haste.
[–1]: Creatures you control with flying get +1/+0 and gain vigilance until end of turn.
[–6]: Search your library for any number of creatures with flying and put them onto the battlefield. Shuffle your library.

When Slaug's Warhowler enters, create a 1/1 red Goblin creature token with haste.
When Slaug's Warhowler dies, you may discard a card. If you do, draw a card.

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell with a creature type no creature you control has.

Each opponent sacrifices an artifact or enchantment.
Showcase {2}{G}{G} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Whenever Aukashi, Electric Legacy enters or equipped creature dies, attach Aukashi to a creature you control.
Whenever equipped creature deals damage to a permanent or player, Aukashi deals 2 damage to that permanent or player.
Equipped creature has double strike as long as a creature you controlled died this turn.
Equip {2}

{2}: Carven Guardian gains reach until end of turn.

Flying
Whenever Soli Windreader attacks, tap target creature without flying you don't control.

Vanishing 4 (This permanent enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Doomed Fate leaves the battlefield, if it had no time counters on it, destroy all nonland permanents.

Stormsurge deals 3 damage to any target.
Orchestrate {R} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Look at the top five cards of your library. You may reveal an enchantment or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
{1}{G}: Nightshade Slayer gets +2/+2 until end of turn. Activate only once each turn.

Target creature gets +2/+1 and gains trample until end of turn. Create a tapped Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Target player mills two cards.
Draw a card.
Coalesce {6}{U} (You may cast this from your graveyard for {6}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Whenever another creature you control enters, you may have it gain haste. If you do, return it to its owner's hand at the beginning of the next end step.