Whenever you draw a card, put a +1/+1 counter on Chasm Skulker. When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Skulk (This creature can't be blocked by creatures with greater power.) At the beginning of your upkeep, you may discard all the cards in your hand. If you do, draw that many cards.

Mist-Cloaked Herald can't be blocked.

River Sneak can't be blocked. Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Whenever you draw a card, put a foreshadow counter on Ominous Seas. Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token. Cycling {2} ({2}, Discard this card: Draw a card.)

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

Scry 1. Draw a card.

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

({T}: Add {U}.)

Target player shuffles their graveyard into their library. Draw a card.