Secrets of Strixhaven Promos

Creature — Djinn Wizard

Opus — Whenever you cast an instant or sorcery spell, target player mills three cards. If five or more mana was spent to cast that spell, that player mills ten cards instead.

Exhibition Tidecaller

Creature — Goblin Bard

Menace
Opus — Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature. If five or more mana was spent to cast that spell, add an amount of {R} equal to this creature's power.

Molten-Core Maestro

Secrets of Strixhaven

Creature — Human Wizard

When this creature enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Opus — Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn. If five or more mana was spent to cast that spell, this creature gets +2/+2 until end of turn instead.

Deluge Virtuoso

Copy

Creature — Elemental Horse

Ward {1}, haste
Opus — Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn. If five or more mana was spent to cast that spell, create a token that's a copy of this creature.

Colorstorm Stallion

Creature — Elf Wizard

Opus — Whenever you cast an instant or sorcery spell, draw a card. Then discard a card unless five or more mana was spent to cast that spell.

Muse Seeker

Creature — Human Sorcerer

Opus — Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn. If five or more mana was spent to cast that spell, this creature also gains double strike until end of turn.

Expressive Firedancer

Creature — Orc Sorcerer

Trample
Opus — Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature. If five or more mana was spent to cast that spell, put two +1/+1 counters on this creature instead.

Tackle Artist

Creature — Dwarf Bard

Reach
Opus — Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent. If five or more mana was spent to cast that spell, this creature deals 3 damage to each opponent instead.

Thunderdrum Soloist

Creature — Elemental Bird

Flying, vigilance
Opus — Whenever you cast an instant or sorcery spell, this creature gets +1/+0 until end of turn. If five or more mana was spent to cast that spell, exile the top card of your library. You may play that card until the end of your next turn.

Elemental Mascot

Creature — Elemental Whale

Flying
Opus — Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn. If five or more mana was spent to cast that spell, put three +1/+1 counters on this creature instead.