msem-instigator

Equipped creature gets +1/+0 and has menace.
Equip {3}

Whenever you cast a spell, you may pay {1}. If you do, Wizened Tortle explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Cast this spell only before combat.
At end of combat this turn, return all creatures that attacked or blocked this combat to their owners' hands. If no creatures attacked or blocked this combat, draw two cards.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Mill five cards, then you may exile any number of cards from your graveyard. Create an X/X black Horror creature token with menace, where X is the number of cards exiled in this way. (To mill five cards, put five cards from the top of your library into your graveyard.)

Flash
When Daughter of Tempests enters, target creature an opponent controls gets -2/-0 until end of turn.
Attain {3}{U} ({3}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Look at the top three cards of your library, then put them into your graveyard or back on top of your library in any order.
Draw two cards.

{1}{R/W}: Untap Blade of the Long Night.

Morningstar Blaze deals X damage divided as you choose among one or two targets.

{2}{B}, Exile Lizhao's Soulblade from your graveyard: Return target creature card from your graveyard to your hand. Activate only as a sorcery.

At the beginning of your upkeep, exile the top card of each of your libraries.
Put X cards exiled with Possibility Matrix on the bottom of their owner's library: You may cast a nonland card exiled with Possibility Matrix with mana value X or less without paying its mana cost.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Maddened Elk attacks, it gets +1/+1 until end of turn for each other attacking creature you control.

Choose X. You may choose the same mode more than once.
• Epic of Anku deals 4 damage to each creature.
• You draw three cards and you lose 3 life.
• Return target nonplaneswalker permanent card from your graveyard to the battlefield.

Enchant land
Enchanted land has “{T}: Add {G}{G}.”

As Rhythm of Kaneh enters, choose Andazir or Mahara.
• Andazir — Whenever a creature you control attacks, defending player discards a card.
• Mahara — Whenever a nontoken creature you control dies, amass Soldiers X, where X is that creature's power.

Sacrifice another creature: Blood Bairn gets +2/+2 until end of turn.

Whenever you activate a loyalty ability of Xanigan, the Darkened Cloud, you get an emblem with exalted.
[+2]: Xanigan deals 2 damage to up to one target and you gain 2 life.
[–3]: You draw three cards and you lose 3 life.
[–7]: Xanigan becomes a 7/7 Demon creature with flying and indestructible that's still a planeswalker. Prevent all combat damage that would be dealt to her.

Whenever you lose 2 or more life during your turn, put two blood counters on Hemomancy.
{1}{B}, Remove X blood counters from Hemomancy: Return target creature card with mana value X from your graveyard to the battlefield.

Mindhunter Grizzly can't attack or block unless you scried this turn.
{5}{U}: Scry 1.

Draw a card for each Avatar you control.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
Haste

Scholar of the Staff can't block.
Inspired — Whenever Scholar of the Staff becomes untapped, up to one target creature can't block this turn.

Investigate ten times. (Create ten colorless Clue artifact tokens with “{2}, Sacrifice this artifact: Draw a card.”)

Enchant creature
When Sythian Scripture enters, put two +1/+1 counters on enchanted creature.
Enchanted creature gets +1/+1 and has indestructible and lifelink if you controlled a white legendary creature or planeswalker as you cast Sythian Scripture.

Planar Alignment enters tapped.
{T}: Add {C}.
{6}, {T}, Exile Planar Alignment: Search your library for a card, put it into your hand, then shuffle.