Vortex Sphinx
Creature-Sphinx (M)
Flying
When Vortex Sphinx enters the battlefield, you may shuffle your hand into your library and draw seven cards.
4/4

Reuse -
Enchantment
: Target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Snapcast —
Instant
Target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Bridge the Planes —
Sorcery (M)
Search your library for a permanent card and put it on the battlefield. Then shuffle your library.

Spellweaver —
Creature — Naga Wizard (R)
2/2
When Spellweaver enters the battlefield, you may search your library for an instant or sorcery card, reveal it, and put it into your hand. Then shuffle your library.

Spellcrash —
Instant (R)
Counter target spell. Destroy target artifact.
As Grok feebly watched the magics from his tribal ritual smash into his heirloom ceramic plates, he wasn't sure whether to be more afraid of the mage across the room or the wrath of his grandmother at the next family holiday.

Sorin's Vengeance —
Sorcery (R)
Exile all nonland permanents.
Nahiri had driven Avacyn insane, crippled Sorin for a millennium, and summoned extraplanar beings to ravage his home. When he finally found her, his revenge was absolute.

Righteous Rallier
Creature - Human Citizen
~'s power and toughness are both equal to the number of creatures named ~ you control.
*/*

I feel like this has to have been done before, but I don't recall it.
fake edit- forgot about plague rats. I like this better though.

Timberpack Wolf is similar, but not quite the same.

Far-flung Adventures
Sorcery
Search your library for up to X basic land cards, reveal them, and put them into your hand. Then shuffle your library.

Riding Crop
Artifact - Equipment (U)
Equipped creature has prowess.
Equip

Summoning Seize
Instant
Gain control of target creature spell.

Emulate
Instant (U)
Create a token copy of target creature spell.

Whys that more expensive than Desertion? See also the flexible Gather Specimens

Spell Chop -
Instant
Counter target spell with converted mana cost X+3.

I dunno, something about it just seemed particularly unfun at a lower cost, even if the only real upside is it gets past "can't be countered"

Cat Burglar
Creature - Human Rogue
: Gain control of target creature with power 1.
1/2

there needs to be more non-blue counterspells

Hand of Bureaucracy
Instant (R)
Counter target spell unless its controller pays , where X is the difference between that spell's converted mana cost and the amount of mana spent to cast that spell.
"You're not wrong. There are loopholes in the system. Just, not for you."

you know what, let's just give white everything that used to be in blue's part of the color pie

blue certainly doesn't need it

Charity
Enchantment (M)
At the beginning of each opponent's upkeep, choose another permanent you control. That opponent gains control of the chosen permanent.
The act is its own reward.

Witness the End
Instant (C)
Look at the bottom card of your library. You may put that card on top of your library.
Draw a card.

Riverside Meadow
Land
, Pay 1 life, Sacrifice Riverside Meadow: Search your library for a basic Plains or Island card and put it onto the battlefield. Then shuffle your library.

death to fetchlands

The funny thing is that this is still at least like 70% of the power level of a regular fetchland.

Wakening Hillside
Land (U)
Wakening Hillside enters the battlefield tapped.
When Wakening Hillside enters the battlefield, add to your mana pool.
: Add or to your mana pool.

Nightstalker
Creature - Shade Horror
Menace
When Nightstalker enters the battlefield, destroy up to X creatures.
The longer it waits, the longer it feeds.
4/3

Find Treasure -
Sorcery
Create X colorless Treasure artifact tokens with ", Sacrifice this artifact: Add one mana of any color to your mana pool."