msem-instigator

When this artifact enters, target creature you control seeks secrets. (Give it that Oath Aura. Fulfill it by attacking with it and two or more other creatures to draw a card.)
Equipped creature gets +2/+1. As long as it has an Oath attached to it, it has menace.
Equip {3}

Whenever a nontoken creature you control dies, you may put a +1/+1 counter on target creature. If you do, that creature's controller loses 1 life.

Gain control of target creature with the least power among creatures on the battlefield, then invigorate 2. (Choose a creature with the least power among creatures you control and put two +1/+1 counters on it.)

Choose any number of target nonland permanents each controlled by different players. For each of those permanents, return it to its owner's hand. If you returned a permanent you controlled this way, create a 3/3 green Plant Elemental creature token with reach.

Flying
As long as it's your turn, creatures you control get +3/+0 and have vigilance.
As long as it's not your turn, creatures you control get +0/+3 and have lifelink.

Target creature gets +1/+5 until end of turn.
Draw a card.

Instant, sorcery, and legendary spells you cast cost {1} less to cast.

As long as it's your turn, Ahl the Omenwing is a 2/1 Bird Wizard creature with flying and indestructible. (He doesn't lose loyalty while he's not a planeswalker.)
[+1]: Surveil X, where X is the number of creatures that attacked this turn.
[–2]: Return target nonland permanent to its owner's hand. Draw a card.

Flash (You may cast this spell any time you could cast an instant.)
When Dazzling Voidmage enters, you may return target attacking creature to its owner's hand.

As an additional cost to cast this spell, pay X life.
Ignition Ritual deals X damage to each creature and each planeswalker.

Whenever Tremor Elemental enters or you draw a card except during your draw step, Tremor Elemental deals 1 damage to each creature.

({T}: Add {W} or {U}.)
Bustling Harbor enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Whenever Study Sphere or another artifact or enchantment you control enters, rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

You may play enchantment spells from your graveyard if you haven't cast a spell with that name this turn.
At the beginning of your end step, choose up to one enchantment you control. Shuffle the rest into your library.

Create a 3/3 green Beast creature token, then populate. (Create a token that's a copy of a creature token you control.)

{1}, {T}: Exile target creature you control until Elsewhere Mirror leaves the battlefield. (It returns to the battlefield under its owner's control.)
{3}: Choose a permanent card exiled with Elsewhere Mirror. Target creature becomes a copy of that card until end of turn.

Flying
Ride {3}{U} ({3}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Destroy target enchantment or Zombie.
Cycling {W} ({W}, Discard this card: Draw a card.)

Flash
Enchant creature
Enchanted creature has base power and toughness 0/1 and loses all abilities and creature types.
{2}{U}: Return Fractured Persona to its owner's hand.

Flash
As long as Iroshi entered this turn, you may activate their loyalty abilities any time you could cast an instant.
[+1]: You may return a creature you control to its owner's hand. If you do, draw a card.
[–1]: Create a 2/2 green Ninja creature token.
[–2]: Target creature you control deals damage equal to its power to target creature or planeswalker.

First strike
{T}: Bogclaw Sniper deals 2 damage to target blocking creature.

Trample, haste
When Tyrants of Bundan enters, tap all lands target player controls. They don't untap during their controller's next untap step.

Counter target spell.
At the beginning of your upkeep, if you control three or more creatures with flying, you may return Divine Denial from your graveyard to your hand.

At the beginning of combat on your turn, for each permanent type, aetherize up to one target permanent you control of that type. (To aetherize, create a token that's a copy of it, then exile that token.)

Search your library for a Forest card, put it onto the battlefield, then shuffle.