msem-instigator

Target player sacrifices a creature unless they discard a creature card.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Choose target creature, then choose two —
• The chosen creature gets +3/+0 until end of turn.
• The chosen creature gains trample until end of turn.
• The chosen creature gains first strike until end of turn.

When Syncretic Master enters, look at the top X cards of your library, where X is the number of basic land types among lands you control. Put one them into your hand and the rest into your graveyard.

Exile the top two cards of your library and put a blood counter on each of them. Until the end of your next turn, you may play cards you own in exile with blood counters on them.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

Flying, haste
Miyoga Flameweaver can't block.
Whenever Miyoga Flameweaver attacks, exile the top card of your library. You may play that card until end of turn.

Creatures with power equal to the number of cards in your hand can't attack.

Whenever a creature dealt damage by Slave Child this turn dies, you may pay {B}. If you do, transform Slave Child.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Dawn Over Avaz enters, it deals 3 damage to each creature.

Target player sacrifices an enchantment. You gain 4 life.

Flying
Whenever Rimebreath Tyrant attacks, you may discard a card. When you do, tap target creature. It doesn't untap during its controller's next untap step.

Rapport — Whenever Aelinn, Serpent's Voice and at least one other creature you control become tapped, reveal the top card of your library. You may cast that card. If you don't, put it into your graveyard and Aelinn, Serpent's Voice deals 2 damage to each opponent.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
Whenever Fervent Ensign attacks, add {R} at the beginning of your next main phase.

When Scrollmaster dies, you may exile it. If you do, search your library for an instant or sorcery card with mana value 4 or less and cast it without paying its mana cost. If you searched your library this way, shuffle.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Flamethrower deals 4 damage to any target.

At the beginning of your upkeep, each opponent mills cards equal to the number of card types among permanents you control.

[+1]: You may play an additional land this turn.
[–1]: Discard a card. If you do, return target creature, land or sorcery card from your graveyard to your hand.
[–5]: Create Thrice-Folded Lotus, a colorless Masterpiece artifact token with “{T}: Add three mana of any one color.” and “{3}, {T}: This artifact deals 3 damage to any target.”

Ashthread Alley enters tapped.
{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice Ashthread Alley: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Sammel Wyldjack enters with a fuse counter on him.
At the beginning of your upkeep, remove a fuse counter from Sammel Wyldjack. If you do, each player sacrifices four lands and Sammel Wyldjack deals 4 damage to each other creature.

Equipped creature gets +2/+1.
When equipped creature deals combat damage to an opponent, you may sacrifice Cursebreaker Hammer. If you do, destroy target artifact or enchantment that player controls.
Equip {2}

Pressure—{B}, Pay 5 life. (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Create an X/X black Horror creature token, where X is the number of cards in your graveyard.

Noxious Garden enters tapped.
As Noxious Garden enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that permanent would die this turn, exile it instead.

When Goblin Twinblades enters, create a 1/1 red Goblin creature token.

When Dawnhart Ceremony enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Invocation — When you spend four or more mana to cast a spell or activate an ability during your turn, transform Dawnhart Ceremony.