Yris' Invocation
Instant
Target creature gains protection from the color of your choice until end of turn.
If that creature is green, it also gains lifelink until end of turn.

Vogol's Invocation
Instant
Target creature gains indestructible until end of turn.
If that creature is green, it also gains deathtouch until end of turn.

Joshua's Invocation
Instant
Target creature gets +3/+2 until end of turn.
If that creature is blue, it also gains hexproof until end of turn.

Tritia's Invocation
Instant
Target creature gets +0/+4 until end of turn.
If that creature is red, you may switch its power and toughness until end of turn.

Eriel's Invocation
Instant
Target creature gets +2/+1 until end of turn.
If that creature is white, you may have it gain first strike until end of turn.

Oszar's Trickery
Instant
Choose one:
-Counter target spell with an odd converted mana cost.
-Destroy target creature with an even converted mana cost.

Pellium's Gambit
Instant
Choose one:
-Target nonland permanent gains indestructible until end of turn.
-Return target nonland permanent to its owner's hand.

Eriel's Will
Instant
Choose one:
-Prevent all combat damage that would be dealt this turn.
-If a creature would deal combat damage this turn, it deals twice that much damage instead.

Inspired by your odd/even thing:


Instant
Choose target spell and roll a six-sided die. If that spell's converted mana cost is less or equal to the number on the die, counter it. Otherwise return ~ to its owner's hand.

Fire-Tamed Dotard
Creature - Beast
Fire-Tamed Dotard can't attack or block unless it's been dealt damage this turn.
4/5

I feel like Fire-Tamed Dotard could be pushed to "Constructed meme deck" power, with a high upside if you can consistently pull off the condition. A rare 5/5 with trample seems reasonable.

Gauntlet of Blight
Artifact
As ~ enters the battlefield, choose a color.
Creatures your opponents control of the chosen color get -1/-1
Whenever a land an opponent controls is tapped for mana of the chosen color, it doesn't untap during its controller's next untap step.

The Librarian
Legendary Creature - Human Advisor
Whenever ~ deals combat damage to a player, you may reveal a card from your hand. If you do, search your library for a card that shares a name with it, reveal it, then shuffle your library and put that card on top of it.
2/2
A place for everything, and everything in its place.

Let's try this again, EDH style:

The Librarian
Legendary Creature - Human Advisor
Whenever ~ deals combat damage to a player, you may reveal a card from your hand. If you do, search your library for a card that shares a converted mana cost as that card, reveal it, then shuffle your library and put that card on top of it.
2/2
A place for everything, and everything in its place.

Borrowed Books
Sorcery
Each opponent reveals their hand, and you choose a card from each of them, and exile those cards. You may look at and play those cards as long as they remain exiled, and you may spend mana as though it were mana of any color to play those cards.

Abridging
Enchantment
Instant and Sorcery spells you cast with converted mana cost 5 or greater cost less to cast.

Forbidden Tome
Sorcery
Destroy all creatures, then return up to one creature card from a graveyard to the battlefield under your control.

Sequel
Enchantment
Sacrifice ~: Copy target instant or sorcery spell. You may choose new targets for the copies.

Ancestral Vision

Reading Glasses
Artifact
: Add or to your mana pool.
, : Draw a card, then discard a card.

Syphon Flesh

Overdue
Instant
Shuffle target creature into its owner's library.

Bookkeeper
Creature - Fairy Wizard
Flying
Whenever you cast an instant or sorcery spell, ~ gets +X/+X until end of turn, where X is that spell's converted mana cost.
1/2

Bookshelf
Creature - Wall
Defender
Whenever ~ blocks a creature, you may cast an instant or sorcery card from your graveyard with converted mana cost less than or equal to that creature's power without paying its mana cost. If you do, shuffle it into its owner's library as it resolves.
0/7

Paperback
Artifact Creature - Boar
When ~ enters the battlefield, search your library for up to 2 basic land cards, put them into your hand, then shuffle your library.
When ~ dies, you may put up to 2 basic land cards from your hand onto the battlefield.
2/2

Running Ink
Instant
Counter target spell. Creatures that spell's controller controls get -X/-X until end of turn, where X is that spell's converted mana cost.

Librarian commander continued:

Barren Moor
Fetid Pools
Lonely Sandbar
Drowned Catacomb
Underground Sea
Watery Grave
Temple of Deceit
Creeping Tar Pit
Maze of Ith
Command Tower
Sunken Ruins
Dimir Aqueduct

Inkwell
Land
~ enters the battlefield tapped.
: Add to your mana pool.
: Add to your mana pool. Spend this mana only to cast instant or sorcery spells with converted mana cost 5 or greater.

Typhoid Rats
Sol Ring
Tragic Slip
Wayfarer's Bauble
Enclave Cryptologist

Go For the Throat
Wall of Ideas

Cat Burglary

Solemn Simulacrum
Damnation

Raise the Fallen
Metallurgic Summonings

Reign of the Pit

Fog Bank

The Returns
Creature - Skeleton Wizard
Whenever you cast an instant or sorcery spell with converted mana cost 5 or greater, return ~ from your graveyard to the battlefield.
4/3

Nevinyrral's Disk

Tidings

Mystery Novel
Sorcery
Reveal the top card of your library. If it's an instant or sorcery card, you may cast it without paying its mana cost. Otherwise, put it into your hand.

Folk Tales
Sorcery
Draw a card for each creature your opponents control. You get an emblem with "you have no maximum hand size".

Spelltwine

Captivating Story
Sorcery
Each opponent reveals their hand, and you choose a creature card from one of those players' hands and put it onto the battlefield under your control.

Blatant Thievery
Diluvian Primordial
Sepulchral Primordial

Decree of Pain

Paper Cuts
Enchantment
Whenever you cast an instant or sorcery spell, each opponent loses life equal to its converted mana cost, and you gain life equal to the total life lost this way.

Neverending Story
Sorcery
Draw 3 cards and take an extra turn after this one.

Rise of the Dark Realms

The End
Sorcery
Exile all instant and sorcery cards from all graveyards. Until end of turn, you may cast those cards without paying their mana costs. Exile ~.

Dimir Signet

Blood Acolyte
Creature - Human Wizard
Deathtouch
When ~ dies, you may cast an instant or sorcery card from your hand without paying its mana cost.
3/3

Plague Wind

Ok, so as it stands, the curve is as follows:

0 1
1 5
2 7
3 6
4 4
5 7
6 4
7 5
8 3
9 3
Total: 45

Based on the official mtg commander decks, I should have about 61 total nonland cards.

Doubling Cube
Divination

Dimensional Horror
Creature - Horror Illusion
Flying
Whenever a player casts an instant or sorcery spell, exile ~ and return it to the battlefield at the beginning of the next end step.
5/5

Dust Jacket
Enchantment
Sacrifice ~: Counter target spell that targets a player or permanent.

Late Fees
Enchantment
Creatures can't attack you or planeswalkers you control unless their controller pays for each attacking creature.
Creatures can't block creatures you control unless their controller pays for each blocking creature.
Spells that target you or permanents you control cost more to cast.

Toxic Deluge

Fact or Fiction
No Mercy
Thran Dynamo

Brain in a Jar

Book Worms
Sorcery
Create two 1/1 black worm creature tokens with deathtouch.

Exchange Student
Creature - Human Wizard
Whenever a creature blocks or becomes blocked by ~, exchange control of ~ and that creature.
1/1

Baleful Strix

Invisible Ink
Enchantment - Aura
Enchant Creature
Enchanted creature has skulk and "whenever this creature deals combat damage to a player, draw a card".
Whenever a creature with power 2 or less enters the battlefield under your control, you may return ~ from your graveyard to your hand.

Echo Mage

Army of the Dead
Sorcery
Put target creature card from a graveyard onto the battlefield under your control, then put 2 tokens onto the battlefield that are copies of that creature.

10 Swamp
15 Island

And that's the deck!

Library Card
Artifact
,T: Draw a card. At the beginning of the next end step, put a card from your hand on the bottom of your library.

Frostiron Chieftain
Creature - Human Warrior
At the beginning of your upkeep, put a -1/-1 counter on target creature an opponent controls.
Each creature you control gets +1/+1 for each creature your opponents control with a -1/-1 counter on it.
2/2

Fledgling Witch
Creature - Human Wizard
Trample
: Search your library for a creature card with converted mana cost X, exile it, then shuffle your library. ~ becomes a copy of that creature, except it gains trample and this ability.
2/2

Devious Witch
Creature - Human Wizard
Deathtouch
, sacrifice another creature with converted mana cost X: Search your library for an instant or sorcery spell with converted mana cost X. You may cast that card without paying its mana cost. Then, shuffle your library. Activate this ability only during your upkeep.
2/2

Imperious Witch
Creature - Human Wizard
Extort
Spells you cast that target spells and permanents your opponents control cost less to cast.
2/2

Clockworker Witch
Creature - Human Wizard
Whenever you cast a spell, you may pay . If you do, create a 1/1 colorless servo artifact creature token.
~ gets +1/+1 for each servo you control.
2/2


Dazzling Witch
Creature - Human Wizard
Prowess
Other creatures you control have protection from converted mana cost less than ~'s power.
2/2

Daredevil Witch
Creature - Human Wizard
Haste
Whenever a creature enters the battlefield under your control, that creature can't be blocked this turn.
2/2

Hungry Witch
Creature - Human Wizard
Hexproof
Whenever another permanent is put into a graveyard from the battlefield, you may exile it. If you do, you gain 2 life.
2/2

Lackey Witch
Creature - Human Wizard
Menace
Whenever ~ attacks or blocks, you may have its base power become equal to the greatest power among creatures you control.
2/2

Vanilla Witch
Creature - Human Wizard
Flying
2/3

Fledgling, Devious and Lackey are my favourites.
Hungry Witch seems more BG than UG. MAybe casting spells grants creatures hexproof? I dunno.
Clockworker Witch should probably only trigger off a specific spell type. Ins/orceries or artifacts- it could go either way. Is she making magic from metal or magicalling up the metal?

Hungry witch was originally BG, but then I made Lackey Witch and had to change the color. I tagged on the hexproof to make it blue, with the triggered ability being green.