Kalamax, the Stormsire

Whenever you cast your first instant spell each turn, if Kalamax, the Stormsire is tapped, copy that spell. You may choose new targets for the copy.
Whenever you copy an instant spell, put a +1/+1 counter on Kalamax.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Aim High

Untap target creature. It gets +2/+2 and gains reach until end of turn. (It can block creatures with flying.)

Counterspell

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

Growth Spiral

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

Niblis of the Breath

Flying
{U}, {T}: You may tap or untap target creature.

Puppet Strings

{2}, {T}: You may tap or untap target creature.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Chain Stasis

You may tap or untap target creature. Then that creature's controller may pay {2}{U}. If the player does, they may copy this spell and may choose a new target for that copy.

Refocus

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Simic Signet

Seedborn Muse

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

Arcane Signet

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

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Disallow

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Dramatic Reversal

Untap all nonland permanents you control.

Seeker of Skybreak

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

Puppeteer

{U}, {T}: You may tap or untap target creature.

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.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Wilderness Reclamation

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

Evolution Charm

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Return target creature card from your graveyard to your hand.
• Target creature gains flying until end of turn.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Sol Ring

Gruul Signet

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Early Frost

Bounding Krasis

Flash (You may cast this spell any time you could cast an instant.)
When Bounding Krasis enters the battlefield, you may tap or untap target creature.

Fyndhorn Brownie

Toils of Night and Day

You may tap or untap target permanent, then you may tap or untap another target permanent.

Artifact Mutation

Destroy target artifact. It can't be regenerated. Create X 1/1 green Saproling creature tokens, where X is that artifact's mana value.