Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Frilled Mystic

Flash
When this creature enters, you may counter target spell.

Fyndhorn Elves

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Hullbreacher

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Noxious Revival

({G/P} can be paid with either {G} or 2 life.)
Put target card from a graveyard on top of its owner's library.

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Arcane Signet

Sol Ring

Forest

Unwind

Counter target noncreature spell. Untap up to three lands.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Island

Llanowar Elves

Mystic Snake

Flash
When this creature enters, counter target spell.

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.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Tidal Barracuda

Any player may cast spells as though they had flash.
Your opponents can't cast spells during your turn.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.