Have

Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Rootha, Mercurial Artist

{2}, Return Rootha, Mercurial Artist to its owner's hand: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

Debating

Third Path Iconoclast

Whenever you cast a noncreature spell, create a 1/1 colorless Soldier artifact creature token.

Sol Ring

Storm Skreelix

Flying
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, Storm Skreelix gets +2/+0 until end of turn.

Ponder

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

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Fiery Fall

Fiery Fall deals 5 damage to target creature.
Basic landcycling {1}{R} ({1}{R}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Zaffai, Thunder Conductor

Magecraft — Whenever you cast or copy an instant or sorcery spell, scry 1. If that spell's mana value is 5 or greater, create a 4/4 blue and red Elemental creature token. If that spell's mana value is 10 or greater, Zaffai, Thunder Conductor deals 10 damage to an opponent chosen at random.

Island

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Umara Mystic

Flying
Whenever you cast an instant, sorcery, or Wizard spell, Umara Mystic gets +2/+0 until end of turn.

Mountain

Brainstorm

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