The triggered ability triggers just once, no matter how many creatures died this turn
The Deck Creatures (27) 4 Lord of Atlantis 4 Merrow Reejerey 4 Silvergill Adept 4 Cursecatcher 1 Sygg, River Cutthroat 2 Phantasmal Image 4 Master of the Pearl Trident 2 Thassa, God of the Sea 2 Master of Waves Lands (20) Spells (13) Sideboard Lets break the deck down piece by piece
And with the More Than Meets the Eye ability, you can bring them out onto the battlefield directly as their alternate non-robot form
Still, they may be difficult to include in formats in a flavorful way
Modern , Vintage, Legacy, and Pioneer: These are called eternal formats because the legal cards dont change
This can be especially helpful early on to get some lore on the table before your heavy hitters can gain traction