Elemental Masterpiece

Create two 4/4 blue and red Elemental creature tokens.
{U/R}{U/R}, Discard Elemental Masterpiece: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Elemental Summoning

Create a 4/4 blue and red Elemental creature token.

Island

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Arcane Subtraction

Target creature gets -4/-0 until end of turn.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Eroded Canyon

Eroded Canyon enters tapped.
When Eroded Canyon enters, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

Make Disappear

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Counter target spell unless its controller pays {2}.

Leap of Flame

Replicate {U}{R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Target creature gets +1/+0 and gains flying and first strike until end of turn.

Hard Evidence

Create a 0/3 blue Crab creature token.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Lorehold Pledgemage

First strike
Magecraft — Whenever you cast or copy an instant or sorcery spell, Lorehold Pledgemage gets +1/+0 until end of turn.

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Prismari Pledgemage

Defender
Magecraft — Whenever you cast or copy an instant or sorcery spell, Prismari Pledgemage can attack this turn as though it didn't have defender.

Quandrix Pledgemage

Magecraft — Whenever you cast or copy an instant or sorcery spell, put a +1/+1 counter on Quandrix Pledgemage.

Mountain

Introduction to Prophecy

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.