KirriCorp

Jellyfish swarm is designed to build up a tidal force of creatures, weak individually, that can swarm and overcome an enemy, making strong defenses irrelevant. I selected cards that would hamper the growth and potential actions of the enemy (Darts Anemone, Ghost Jellyfish), as well as a few suited to quickly taking out blockers and letting the 'wave' of creatures crash down unopposed. The higher-cost creatures (Imperial Blue, Slasher Antlion) have the purpose of removing or circumventing a strong defense.

Current testing has shown that the deck works about as intended, but has issues overcoming decks that also try to swarm with smaller creatures quickly, since the defenses and spells that are in place are designed to counter fewer, stronger creatures (Ghost Jellyfish, Impel End).

I'd appreciate any suggestions on how to offset the weakness against other swarm-type deckbuilds, or how to optimize my capacity at overwhelming other deck types, or just suggestions in general since I'm still new to this online card game thing .

Creatures (28, Gravity 22, Water 6):

Ghost Jellyfish x4
Jonas x2
Indigo x2
Amnesia Worm x3
Imperial Blue x2
Darts Anemone x4
Ink Balloon x4
Kraken Eleganto x2
Nightmare Echo x2
Slasher Antlion x3

Spells (10, Fire 3, Lightning 3, Gravity 4):

Mark Arrow x3
Action Bolt x3
Impel End x2
Wormhole x2

Runes (2, Water 2):

Stealth Matrix x2

The Gravity rune can be interesting to run .

Also look into Sentient Gorge for potent abusal.

Looking at it carefully now, I don't think you NEED the Nightmare Echo, if you do make changes, those can probably be the first to go.

More revival methods (From The Depths perhaps) would let you use your creatures to attack theirs even if you lose yours in the process, but does not solve the issue of an enemy swarm that is not attacking so you might need to still look into that.

Myraaaa you made a deeeeeck!! Yooo!!

In my books, Riptide Reef is effective swarm control

I love it!