Kuberr, Numena of Avarice
Legendary Enchantment Creature — Avatar
Effects from abilities of creatures named Dark Supplicant count Kuberr, Numena of Avarice as a card named Scion of Darkness. If this effect would put Kuberr on the battlefield, instead create three Treasure tokens then put Kuberr on the battlefield.
Kuberr gets +1/+1 for each Treasure you control.
Whenever a creature dies, create a Treasure token.
0/0

I came up with a few ideas for r here


Sudden Shift -
Instant
Split second
Target player shuffles their library.


Fatesealed Efreet -
Creature - Efreet
Haste
When ~ enters the battlefield, an opponent looks at the top card of your library. They may put that card on the bottom of your library.
6/4


Morin the Unwary -
Legendary Creature - Human Warrior
Creatures you control can't be the target of spells or abilities you control.
5/4

Nantuko Wisdom
Sorcery
Look at the top five cards of your library. Reveal up to one creature or land card from among those cards, put it into your hand, and put the rest in your graveyard. Then, if you cast this spell from your graveyard, return up to one card from your graveyard to your hand.
Flashback
"We all pupate in the wisdom of our elders." — Thriss, Nantuko Primus

Teferi the Fool -
Planeswalker - Teferi
+1: Draw two cards, then discard a card.
-4: ~ deals damage to any target equal to the number of cards in your graveyard.
Madness
3

The Mirari-Sword
Legendary Artifact — Equipment
Equipped creature gets +3/+0.
Whenever equipped creature deals combat damage, add that amount of . This mana doesn't empty as phases and steps end until end of turn. The next time you spend any of this mana to cast a spell, copy that spell. You may choose new targets for the copy.
Equip

Timeline
Land
: Remove a time counter from target permanent or suspended card.
It is not where, but when.

Lorwyn/Shadowmoor

Kithshield
Instant
Dawn (When you cast this card's dawn side, transform all permanents you control with dusk.)
Target creature with power 3 or less gains indestructible and hexproof until end of turn.
"Our unity is to preserve who we are."

Kithsword
Instant
Dusk (When you cast this card's dusk side, transform all permanents you control with dawn.)
Destroy target creature with power 4 or greater.
"Our unity is to destroy what threatens us."

Shared Wings -
Enchantment
Each creature you control that shares a creature type with another creature you control has flying.

Herald is the inverse of Evoke. You pay extra to get a 2/2 creature with the instant/sorcery ability.
The color of the Elemental creature token would change with the color of the spell itself.

Two versions - common for limited or uncommon for constructed:

Ok but it should be Tribal - Elemental so it still interacts with Flamekin Harbinger


Finding Keeper -
Creature - Goblin
, , Discard a card: Draw a card.
1/1

Sapbrew
Sorcery
Dawn (When you cast this card's dawn side, transform all permanents you control with dusk.)
Put a number of +1/+1 counters on target creature equal to its power.
Treefolks make their potions from their own sap and fruit and distills their own patience and benevolence into pure liquid.

Cankercurse
Sorcery
Dusk (When you cast this card's dusk side, transform all permanents you control with dusk.)
Target creature you control gains wither until end of turn. It fights target creature you don't control.
A treefolk's curse is ancient, silent, and root-deep.

Inspired by Dinrova Horror or -to stay on Lorwyn/Shadowmoor- River's Grasp.


This might need to be a sorcery to be balanced:

Clashing Cymbal -
Artifact
When ~ enters the battlefield, scry 2.
, Tap an untapped creature you control: Add one mana of any color.

Ancient Orchard
Tribal Land — Treefolk Forest
Ancient Orchard enters the battlefield tapped.
: Ancient Orchard becomes a black, green, and white 2/5 Treefolk creature with vigilance and deathtouch until end of turn. It's still a land.
A bitter fruit ferments into a sweet release.

Next is Alara

Twin-Armed Paladin —
Creature — Human Knight (R)
Exalted
Vigilance
Your exalted abilities trigger whenever a creature you control blocks alone as well as whenever a creature you control attacks alone.
1/1

Sprawling Jellyfish -
Creature - Jellyfish
~’s power is equal to the number of Islands, Swamps, and/or Mountains you control.
When ~ enters the battlefield, return target creature an opponent controls to its owner’s hand.
Unearth
*/1

Gravefruit Crawler
Creature — Fungus Beast
Devour 2
When Gravefruit Crawler dies, return a creature card with power equal to or less than Gravefruit Crawler's power from your graveyard to the battlefield.
2/2

Molten Shards -
Sorcery
Choose one or more -
- ~ deals 3 damage to target colorless creature.
- ~ deals 3 damage to target monocolored creature.
- ~ deals 3 damage to target multicolored creature.
- ~ deals 3 damage to target planeswalker.
- ~ deals 3 damage to target player.

Topan Paragon
Creature — Human Knight
Exalted
Whenever a creature you control attacks alone, its base power and toughness becomes 5/5 until end of turn.
"Eos claims our watering holes but our unity with the leotau speaks to our heritage claim to these lands."
1/1

I've been on a kick re-imagining set keywords from past sets. This is effectively the opposite of exalted, for instance.