Rare

Categorical Ultimatum
Sorcery (M)
Target opponent chooses a card type. Until end of game, they can't cast spells that aren't of the chosen type and spells you cast that aren't of the chosen type cost less to cast.
"We can never be accused of not hearing your concerns." —Trigori, Azorius senator

Oddly Realistic Statue —
Artifact (C)
Champion a creature (When this enters the battlefield, sacrifice it unless you exile a creature you control. When this leaves the battlefield, that card returns to the battlefield.)
: Add two mana in any combination of the championed creature's colours.
, , Sacrifice Oddly Realistic Statue: Draw a card.
Furt's ogre sculpture was the pride of the town — until it rained.

Cabaretti Cake
Artifact - Food (U)
Champion a creature.
, , Sacrifice ~: You gain 3 life.
When ~ leaves the battlefield, the next creature that enters the battlefield under your control this turn gains haste, hexproof, and unblockable until end of turn.

Mishra's Sentinel

Artifact {R}
Whenever another permanent you control becomes the target of a spell or ability an opponent controls, sacrifice it and that spell or ability's controller sacrifices a permanent.
"Such wardens provided no actual defense -- the statues would glare balefully down, unmoving, as their charges were slaughtered. They did, however, always exact a price, and ensure that if Mishra could not have something, no one could." - The Antiquities War

Birth of a Titan
Enchantment — Saga (M)
I - Create three 0/1 Eldrazi Spawn creature tokens with "Sacrifice this creature: Add ."
II, III, IV - Exile target permanent that's one or more colors.
V - Exile and return it to the battlefield transformed.

Gordumar, Born of Eternities
Legendary Creature — Eldrazi
Whenever Gordumar attacks, you may pay . If you do, you may put a face-up permanent card an opponent owns in exile onto the battlefield except it's colorless and it's an Eldrazi if it's a creature.
Whenever one or more creatures block Gordumar, exile one of them.
If Gordumar would be put into the graveyard from anywhere, exile it then put it on the battlefield.
12/12

Land

Barren Taiga
Land (C)
~ enters the battlefield tapped.
: Add or
Mountain cycling
Forest cycling

Towabara Undermarket
Land (U)
Towabara Undermarket enters the battlefield tapped.
: Add . If this mana is spent to cast an artifact or enchantment spell, note each of its types that hasn't been noted with Towabara Undermarket.
, , Sacrifice Towabara Undermarket: Return target creature card from your graveyard to your hand. Activate this ability only if both artifact and enchantment have been noted with Towabara Undermarket.
"The past and the future are merely two ends of a chain to beat your enemy's skull in with." — Greasefang

Ashes of Kroog
Land {R}
, Sacrifice Ashes of Kroog: Add
Whenever a land not named Ashes of Kroog is put into your graveyard from the battlefield, you may return Ashes of Kroog from your graveyard to the battlefield.

Throne of Eldraine
Legendary Land (M)
, : Choose a color. Add X mana of that color, where X is the number of cards you own in exile with an Adventure.

Send on a Quest
Sorcery — Adventure
Adamant — Create a 2/2 white Knight creature token with vigilance. If at least three white mana was spent to cast this spell, also create a 1/1 white Human creature token.

White

Respite
Instant (C)
Prevent all damage that would be dealt to any target this turn.

Gracious Host
Creature — Human Noble (U)
When Gracious Host enters the battlefield, you and an opponent each draws a card. If the opponent drew a nonland card this way, it perpetually gains "This spell costs more to cast."
"Oh, my doors are always open to the weak and destitute, the most unfortunate among us."
2/2

Clear the Record
Sorcery (R)
Destroy all creatures. Prevent all damage that would be dealt until the beginning of your next upkeep.
"When can we quit and go to the country? When no witnesses are left to point their grubby fingers at us."

Champion of Ardenvale
Creature — Human Knight (M)
Double strike
When Champion of Ardenvale dies, it perpetually gets -2/-2 and perpetually loses double strike and this ability. Target creature you control perpetually gets +2/+2 and perpetually gains double strike, lifelink, and this ability.
"Extinguish an ember and the flame yet burns."
2/2

Stutter Step
Instant (C)
Return target creature to its owner's hand. It perpetually gains "This spell costs more to cast."

Helpful Librarian
Creature — Vedalken Wizard (U)
Whenever you seek a card for the first time each turn, put a +1/+1 counter on Helpful Librarian and untap it.
"It's got to be back here."
2/2

When Gerian Upset the Faerie King —
Enchantment — Aura Curse Saga (R)
Enchant player
I: Enchanted player reveals his or her hand.
II: Enchanted player can't cast spells this turn.
III: Look at the top card of enchanted player's library. You may put it into his or her graveyard.
IV: You control enchanted player this turn.

Atemsis, Who Sees Nothing New
Legendary Creature — Sphinx Wizard (M)
If you would seek a card while this card is in your library, you may put this card in your hand instead.
Flying, ward where X is Atemsis's power
Atemsis and other Sphinxes you control get +1/+1 for each card in your hand.
Whenever Atemsis attacks, seek a card with a different mana value than the cards in your hand.
0/0

Stitched of Despair
Creature — Zombie (C)
When Stitched of Despair dies, each opponent gains a boon with "The next time a creature enters the battlefield under your control, it perpetually gets -1/-1."
The skabaren do much work to make their creations and to bring movement to their limbs. The ghoulcallers simply sing to the urge remaining in the bones and rot to share their fate with others.
1/1

Mandragora Banshee
Creature - Plant Spirit (u)
Deathtouch, Flying
Sacrifice another creature you control: ~ gains Indestructible until end of turn. You may activate this ability only once per turn.
[2/2]

Resentful Stitch-Assistant
Creature — Homunculus (R)
: Creature cards in your graveyard perpetually get +1/+1.
: Creature cards in your graveyard perpetually get "This spell costs less to cast."
"'Rgrtlb, do this.' 'Rgrtlb, do that.' 'Rgrtlb, I carved you from the flesh of my own body and drowned a man to give you his breath. You only exist but for my will.' Whatever."
1/1