Risk Factor

Target opponent may have Risk Factor deal 4 damage to them. If that player doesn't, you draw three cards.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Negate

Wizard's Lightning

This spell costs {2} less to cast if you control a Wizard.
Wizard's Lightning deals 3 damage to any target.

Adeliz, the Cinder Wind

Flying, haste
Whenever you cast an instant or sorcery spell, Wizards you control get +1/+1 until end of turn.

Lightning Stormkin

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)

Dreadhorde Arcanist

Trample
Whenever Dreadhorde Arcanist attacks, you may cast target instant or sorcery card with mana value less than or equal to Dreadhorde Arcanist's power from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Amulet of Safekeeping

Whenever you become the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.
Creature tokens get -1/-0.

Shock

Mountain

Spell Pierce

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

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Saheeli, Sublime Artificer

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
−2: Target artifact you control becomes a copy of another target artifact or creature you control until end of turn, except it's an artifact in addition to its other types.

Ionize

Counter target spell. Ionize deals 2 damage to that spell's controller.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Island

Lightning Strike

Lightning Strike deals 3 damage to any target.

Essence Scatter

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Sorcerous Spyglass

As Sorcerous Spyglass enters the battlefield, look at an opponent's hand, then choose any card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Ghitu Lavarunner

As long as there are two or more instant and/or sorcery cards in your graveyard, Ghitu Lavarunner gets +1/+0 and has haste.

Sentinel Totem

When Sentinel Totem enters the battlefield, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
{T}, Exile Sentinel Totem: Exile all graveyards.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.