Whenever Riptide Pilferer deals combat damage to a player, that player discards a card.

Morph U (You may cast this card face down as a 2/2 creature for 3. Turn it face up any time for its morph cost.)

Morph 1UU (You may cast this card face down as a 2/2 creature for 3. Turn it face up any time for its morph cost.)

When Riptide Survivor is turned face up, discard two cards, then draw three cards.

Put a 2/2 black Zombie creature token onto the battlefield tapped for each instant and sorcery card in your graveyard.

Create a tapped 2/2 black Zombie creature token for each instant and sorcery card in your graveyard.

Delve (Each card you exile from your graveyard while casting this spell pays for 1.)

Return target nonland permanent you control and target nonland permanent you dont control to their owners hands.

River Sneak cant be blocked.

Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Flying

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Tap target creature. Put three stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

When Riverwise Augur enters the battlefield, draw three cards, then put two cards from your hand on top of your library in any order.

When Riverwise Augur enters the battlefield, draw three cards, then put two cards from your hand on top of your library in any order.

This spell costs 2 less to cast if it targets a permanent with mana value 1.

Return target creature or Vehicle an opponent controls to its owners hand.

Draw a card.

Landfall - Whenever a land enters the battlefield under your control, you get (e) (an energy counter).

TAP, Pay six (e): Draw three cards.

Landfall - Whenever a land enters the battlefield under your control, you get (e) (an energy counter).

TAP, Pay six (e): Draw three cards.