Guttersnipe

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

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.)

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Livaan, Cultist of Tiamat

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)

Adeliz, the Cinder Wind

Flying, haste
Whenever you cast an instant or sorcery spell, Wizards you control get +1/+1 until end of turn.

Thassa's Intervention

Choose one —
• Look at the top X cards of your library. Put up to two of them into your hand and the rest on the bottom of your library in a random order.
• Counter target spell unless its controller pays twice {X}.

Keep Safe

Counter target spell that targets a permanent you control.
Draw a card.

Lambholt Ravager

Whenever you cast a noncreature spell, this creature deals 2 damage to each opponent.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Lambholt Raconteur

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Lambholt Raconteur // Lambholt Ravager

Runaway Steam-Kin

Whenever you cast a red spell, if this creature has fewer than three +1/+1 counters on it, put a +1/+1 counter on this creature.
Remove three +1/+1 counters from this creature: Add {R}{R}{R}.

Haze of Rage

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Creatures you control get +1/+0 until end of turn.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Rewind

Counter target spell. Untap up to four lands.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Bury in Books

This spell costs {2} less to cast if it targets an attacking creature.
Put target creature into its owner's library second from the top.

Thermo-Alchemist

Defender
{T}: This creature deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap this creature.

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Unleash Fury

Double the power of target creature until end of turn.

Negate

Vadrik, Astral Archmage

If it's neither day nor night, it becomes day as Vadrik enters.
Instant and sorcery spells you cast cost {X} less to cast, where X is Vadrik's power.
Whenever day becomes night or night becomes day, put a +1/+1 counter on Vadrik.