Consider

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

Prismatic Ending

Converge — Exile target nonland permanent if its mana value is less than or equal to the number of colors of mana spent to cast this spell.

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.

Play with Fire

Play with Fire deals 2 damage to any target. If a player is dealt damage this way, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Mountain

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Bloodfeather Phoenix

Flying
Bloodfeather Phoenix can't block.
Whenever an instant or sorcery spell you control deals damage to an opponent or battle, you may pay {R}. If you do, return Bloodfeather Phoenix from your graveyard to the battlefield. It gains haste until end of turn.

Faithful Mending

You gain 2 life, draw two cards, then discard two cards.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)