Water Wings

Until end of turn, target creature you control has base power and toughness 4/4 and gains flying and hexproof. (It can't be the target of spells or abilities your opponents control.)

Island

Pearl of Wisdom

This spell costs {1} less to cast if you control an Otter.
Draw two cards.

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Reasonable Doubt

Counter target spell unless its controller pays {2}.
Suspect up to one target creature. (A suspected creature has menace and can't block.)

Eroded Canyon

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

Ral, Crackling Wit

Whenever you cast a noncreature spell, put a loyalty counter on Ral.
+1: Create a 1/1 blue and red Otter creature token with prowess.
−3: Draw three cards, then discard two cards.
−10: Draw three cards. You get an emblem with "Instant and sorcery spells you cast have storm." (Whenever you cast an instant or sorcery spell, copy it for each spell cast before it this turn.)

Stormchaser's Talent

(Gain the next level as a sorcery to add its ability.)
When this Class enters, create a 1/1 blue and red Otter creature token with prowess.
{3}{U}: Level 2
When this Class becomes level 2, return target instant or sorcery card from your graveyard to your hand.
{5}{U}: Level 3
Whenever you cast an instant or sorcery spell, create a 1/1 blue and red Otter creature token with prowess.

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

Kindlespark Duo

{T}: This creature deals 1 damage to target opponent.
Whenever you cast a noncreature spell, untap this creature.

Tempest Angler

Whenever you cast a noncreature spell, put a +1/+1 counter on this creature.

Bria, Riptide Rogue

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Other creatures you control have prowess. (If a creature has multiple instances of prowess, each triggers separately.)
Whenever you cast a noncreature spell, target creature you control can't be blocked this turn.

Thundering Falls

({T}: Add {U} or {R}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Blow Off Steam

Blow Off Steam deals 1 damage to any target. (Then exile this card. You may cast the creature later from exile.)

Frolicking Familiar

Flying
Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn.

Frolicking Familiar // Blow Off Steam

Mountain

Rabid Gnaw

Target creature you control gets +1/+0 until end of turn. Then it deals damage equal to its power to target creature you don't control.

Rockface Village

{T}: Add {C}.
{T}: Add {R}. Spend this mana only to cast a creature spell.
{R}, {T}: Target Lizard, Mouse, Otter, or Raccoon you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

Spirebluff Canal

This land enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Stormsplitter

Haste
Whenever you cast an instant or sorcery spell, create a token that's a copy of this creature. Exile that token at the beginning of the next end step.

Otterball Antics

Create a 1/1 blue and red Otter creature token with prowess. If this spell was cast from anywhere other than your hand, put a +1/+1 counter on that creature. (Whenever you cast a noncreature spell, a creature with prowess gets +1/+1 until end of turn.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)