Dubious Challenge

Look at the top ten cards of your library, exile up to two creature cards from among them, then shuffle. Target opponent may choose one of the exiled cards and put it onto the battlefield under their control. Put the rest onto the battlefield under your control.

Dynavolt Tower

Whenever you cast an instant or sorcery spell, you get {E}{E} (two energy counters).
{T}, Pay {E}{E}{E}{E}{E}: Dynavolt Tower deals 3 damage to any target.

Disappearing Act

As an additional cost to cast this spell, return a permanent you control to its owner's hand.
Counter target spell.

Ceremonious Rejection

Weldfast Wingsmith

Whenever an artifact enters the battlefield under your control, Weldfast Wingsmith gains flying until end of turn.

Underdark Basilisk

Select for Inspection

Return target tapped creature to its owner's hand. Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Aether Tradewinds

Return target permanent you control and target permanent you don't control to their owners' hands.

Forest

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Woodweaver's Puzzleknot

When Woodweaver's Puzzleknot enters the battlefield, you gain 3 life and get {E}{E}{E} (three energy counters).
{2}{G}, Sacrifice Woodweaver's Puzzleknot: You gain 3 life and get {E}{E}{E}.

Nimble Innovator

When Nimble Innovator enters the battlefield, draw a card.

Empyreal Voyager

Flying, trample
Whenever Empyreal Voyager deals combat damage to a player, you get that many {E} (energy counters).

Tasha's Hideous Laughter

Each opponent exiles cards from the top of their library until that player has exiled cards with total mana value 20 or more.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Prophetic Prism

When Prophetic Prism enters the battlefield, draw a card.
{1}, {T}: Add one mana of any color.

Island

Take Down

Choose one —
• Take Down deals 4 damage to target creature with flying.
• Take Down deals 1 damage to each creature with flying.

Aether Theorist

When Aether Theorist enters the battlefield, you get {E}{E}{E} (three energy counters).
{T}, Pay {E}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Riparian Tiger

Trample
When Riparian Tiger enters the battlefield, you get {E}{E} (two energy counters).
Whenever Riparian Tiger attacks, you may pay {E}{E}. If you do, it gets +2/+2 until end of turn.

Djinni Windseer

Flying
When Djinni Windseer enters the battlefield, roll a d20.
1—9 | Scry 1.
10—19 | Scry 2.
20 | Scry 3.

Attune with Aether

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You get {E}{E} (two energy counters).

Rimeshield Frost Giant

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Longtusk Cub

Whenever Longtusk Cub deals combat damage to a player, you get {E}{E} (two energy counters).
Pay {E}{E}: Put a +1/+1 counter on Longtusk Cub.

Cowl Prowler

Highspire Artisan

Reach (This creature can block creatures with flying.)
Fabricate 1 (When this creature enters the battlefield, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Hunt the Weak

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)