Inferiority Complex
Enchantment - Aura
Enchant creature
At the beginning of each upkeep, enchanted creature gets -X/-X until end of turn, where X is the greatest power among creatures you control.

I wanted to make a card that could hose treasure/artifact/food tokens without being narrowly limited to them.

Spreading Blight
Sorcery
Destroy any number of nonland permanents with total mana value 4 or less.

Rebellion
Creature - Elemental Incarnation
Whenever a creature dies, its controller creates a red aura curse enchantment token with "at the beginning of enchanted player's upkeep, this permanent deals 1 damage to that player."
5/5

Trusty Sidearm
Artifact - Equipment
Equipped creature gets +1/+1
Whenever an equipment becomes unattached from a creature you control, you may attach Trusty Sidearm to that creature.
Equip

Get in the Robot
Instant
Untap target vehicle you control and it becomes a creature. Exile target creature you control as long as you control that vehicle.

Prying Eye
Creature - Eye
Menace
Whenever an opponent reveals their hand, Prying Eye gets +2/+0 until end of turn.
1/2
"Dont be afraid; I'll keep looking at you for ever and ever, without a flutter of my eyelids, and you'll live in my gaze like a mote in a
sunbeam."
-Jean-Paul Sartre, No Exit

Mana Siphoner
Creature - Elf Druid Wizard
: Tap target land and add one mana of any color that land could produce. Until end of turn, you don’t lose this mana as steps and phases end.
3/3
"All great magic is built through collaboration, willing or otherwise."

Seeds of Blight
Instant
Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn.
"It only takes a little push for some people to go over the edge."
-Oszar, Citadel Counsel

Sagas!

Sins of the Father
Enchantment - Saga
I-II: Create a 1/1 white human solider creature token
III: Sacrifice 2 creatures. Put 2 +1/+1 counters on up to one target creature you control, then exile up to one target creature you don't control.

Song of the Elves
Enchantment - Saga
Whenever you put a Lore counter on Song of the Elves, you draw a card and lose 1 life.
I: Create two 1/1 green elf warrior creature tokens.
III: You may have any number of target creatures you control deal damage equal to their power to target creature. If you do, that creature's controller may have it deal damage equal to its power divided as they choose among those creatures.
IV: You may search your library for a legendary land card and put it onto the battlefield tapped. If you do, shuffle your library.

Shifting Strength
Instant
Exchange two target creatures' powers until end of turn.

Disarmament
Enchantment - Aura
Enchant creature
Enchanted creature has base power 1.

Sara, Voice of Vitality
Legendary Creature - Dryad Druid
Trample
Creatures you control get +1/+1 for each +1/+1 counter on them.
2/2

Ezuri Evolved
Legendary Creature - Phyrexian Elf Warrior
: Put a First Strike, Lifelink, Flying, Deathtouch, or Hexproof counter on target creature you control. Then, put a -1/-1 counter on that creature.
3/3
"Vorinclex was wrong, it is not always the strongest who survive."

Scheming Courtier
Creature - Human Advisor
When Scheming Courtier enters the battlefield, search your library for a card, then shuffle and put that card third from the top.
When Scheming Courtier dies, mill three cards.
1/1
"A royal cabinet, like a garden, must have its weeds pulled before they go to seed."
-Sodrovar, Shadow Emperor

Heris, Timekeeper
Legendary Enchantment Creature - Human Wizard
Enchantment spells you control have split second and flash.
2/2
"The blessings of the gods will come in their due time."

Magnetic Suit
Artifact - Equipment
Equipped creature gets +2/+2
Equip abilities that target equipped creature cost less to activate.
Equip

Fight//Flight //
Instant // Instant
Target creature you control fights another target creature.
//
Return target creature you control to its owner's hand and draw a card.

Psychological Horror
Enchantment
At the beginning of your upkeep, you may have each player discard a card.
As long as an opponent has one or fewer cards in hand, Psychological Horror is a 4/4 Horror creature in addition to its other types.
It stalks the hidden corners of your crumbling mind.

Rupture
Enchantment - Aura
Enchant creature
At the beginning of your end step, put a -1/-1 counter on enchanted creature and create a blood token.

Craswell, Buyer of Loyalties
Legendary Creature - Human Advisor
When Craswell enters the battlefield, secretly name a creature card.
Reveal the name you chose: untap and gain control of target creature with the chosen name until your next end step.
2/2
"Loyalty is cheap."

Take Everything
Sorcery
Choose one:
-Destroy all creatures.
-Each player discards their hand.

Twin Dagger
Artifact - Equipment
When Twin Dagger enters the battlefield, if it isn't a token, create a token that's a copy of it.
Equipped creature gets +1/+1
Equip
"How are they going to stop this, two shields?"
-Varax, Dimir Assassin