Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Counterspell

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Mountain

Force Spike

Counter target spell unless its controller pays {1}.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Thought Scour

Target player mills two cards.
Draw a card.

Island

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)