Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Riddlemaster Sphinx

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Riddlemaster Sphinx enters, you may return target creature an opponent controls to its owner's hand.

Plains

Mind Control

Enchant creature
You control enchanted creature.

Arrester's Admonition

Return target creature to its owner's hand.
Addendum — If you cast this spell during your main phase, draw a card.

Thunder Drake

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Thunder Drake.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Island

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Tezzeret, Cruel Machinist

+1: Draw a card.
0: Until your next turn, target artifact you control becomes a 5/5 creature in addition to its other types.
−7: Put any number of cards from your hand onto the battlefield face down. They're 5/5 artifact creatures.

Wall of Runes

Defender (This creature can't attack.)
When Wall of Runes enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Collar the Culprit

Destroy target creature with toughness 4 or greater.

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.

Meandering River

Meandering River enters tapped.
{T}: Add {W} or {U}.

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

War Screecher

Flying
{5}{W}, {T}: Other creatures you control get +1/+1 until end of turn.

Essence Scatter

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Frost Trickster

Flying
When Frost Trickster enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Dovin's Acuity

When Dovin's Acuity enters, you gain 2 life and draw a card.
Whenever you cast an instant spell during your main phase, you may return Dovin's Acuity to its owner's hand.

Radical Idea

Draw a card.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Light of the Legion

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
When Light of the Legion dies, put a +1/+1 counter on each white creature you control.

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

The Wanderer

Prevent all noncombat damage that would be dealt to you and other permanents you control.
−2: Exile target creature with power 4 or greater.

Absorb

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

Metamorphic Alteration

Enchant creature
As Metamorphic Alteration enters, choose a creature.
Enchanted creature is a copy of the chosen creature.

Law-Rune Enforcer

{1}, {T}: Tap target creature with mana value 2 or greater.

Elite Guardmage

Flying
When Elite Guardmage enters, you gain 3 life and draw a card.

Mass Manipulation

Gain control of X target creatures and/or planeswalkers.

Unsummon

Return target creature to its owner's hand.

Finale of Glory

Create X 2/2 white Soldier creature tokens with vigilance. If X is 10 or more, also create X 4/4 white Angel creature tokens with flying and vigilance.

Teyo, the Shieldmage

You have hexproof. (You can't be the target of spells or abilities your opponents control.)
−2: Create a 0/3 white Wall creature token with defender.

Augury Owl

Flying
When Augury Owl enters, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Divination

Serra's Guardian

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)
Other creatures you control have vigilance.