Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Mountain

Inner Fire

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Pyretic Ritual

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)