Najal, the Storm Runner

You may cast sorcery spells as though they had flash.
Whenever Najal attacks, you may pay {2}. If you do, when you next cast an instant or sorcery spell this turn, copy it. You may choose new targets for the copy.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Izzet Signet

Arcane Signet

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

Frostboil Snarl

As this land enters, you may reveal an Island or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {R}.

Seething Song

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Command Tower

Brainstorm

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

Ponder

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

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.