He will typically eat the first removal spell your opponent can cast once he hits the board which is not what you want to happen but also not a disaster
All told, this merfolk has made a heck of a name for themselves
With any new archetype, there are a lot of options to consider, but when the deck can realistically cast almost any spell in Modern, the options can become pretty daunting to try to process
They know exactly what they're doing - this isn't a product for you, this is for FOMO investors to buy out the entire stock and resell them on ebay for an even higher price
Eternal Dragon is a 5/5 flyer for 2 white and 5 colorless mana, plainscycles for 2 colorless, and can be returned to your hand from your graveyard during your upkeep for 2 white and 3 colorless
It's not a game-breaking ability, but a very useful one