Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return Vengevine from your graveyard to the battlefield.

Fiery Islet

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice Fiery Islet: Draw a card.

Arena of Glory

Arena of Glory enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert Arena of Glory: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Lava Dart

Lava Dart deals 1 damage to any target.
Flashback—Sacrifice a Mountain. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Goblin Lore

Draw four cards, then discard three cards at random.

Fear of Missing Out

When Fear of Missing Out enters, discard a card, then draw a card.
Delirium — Whenever Fear of Missing Out attacks for the first time each turn, if there are four or more card types among cards in your graveyard, untap target creature. After this phase, there is an additional combat phase.

Blazing Rootwalla

{R}: Blazing Rootwalla gets +2/+0 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Ox of Agonas

When Ox of Agonas enters, discard your hand, then draw three cards.
Escape—{R}{R}, Exile eight other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Ox of Agonas escapes with a +1/+1 counter on it.

Arclight Phoenix

Flying, haste
At the beginning of combat on your turn, if you've cast three or more instant and sorcery spells this turn, return Arclight Phoenix from your graveyard to the battlefield.

Sunbaked Canyon

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Sunbaked Canyon: Draw a card.

Hollow One

This spell costs {2} less to cast for each card you've cycled or discarded this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Mountain

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.