Case of the Ransacked Lab

Instant and sorcery spells you cast cost {1} less to cast.
To solve — You've cast four or more instant and sorcery spells this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast an instant or sorcery spell, draw a card.

Island

It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Gran-Gran

Whenever Gran-Gran becomes tapped, draw a card, then discard a card.
Noncreature spells you cast cost {1} less to cast as long as there are three or more Lesson cards in your graveyard.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Thirst for Identity

Draw three cards. Then discard two cards unless you discard a creature card.

Caelorna, Coral Tyrant

Illvoi Operative

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Unsummon

Return target creature to its owner's hand.

Scrounging Skyray

Flying
Whenever you discard one or more cards, put that many +1/+1 counters on this creature.
Cycling {2} ({2}, Discard this card: Draw a card.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Mischievous Mystic

Flying
Whenever you draw your second card each turn, create a 1/1 blue Faerie creature token with flying.

Highspire Bell-Ringer

Flying
The second spell you cast each turn costs {1} less to cast.

Boomerang Basics

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Vnwxt, Verbose Host

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
You have no maximum hand size.
Max speed — If you would draw a card, draw two cards instead.

Razzle-Dazzler

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. It can't be blocked this turn.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Monument to Endurance

Whenever you discard a card, choose one that hasn't been chosen this turn —
• Draw a card.
• Create a Treasure token.
• Each opponent loses 3 life.