Wizards has responded with a fun mixture of tact and cheek in a recent post from Blake Rasmussen on the official MTG website
And while they were not on the money, they almost had a hit
The spell also has the added benefit of replacing itself by drawing you a card when it is cast as long as you control at least one merfolk, letting it still maintain its usefulness over the course of a game
Damage marked on permanents won't be removed until you actually get to the cleanup step (which will happen after your second end step), and "until end of turn" and "this turn" effects won't end until the cleanup step either
Aang, Airbending Master Azlask, the Swelling Scourge Azula, Ruthless Firebender Daxos the Returned Ezuri, Claw of Progress Kalemne, Disciple of Iroas Katara, Waterbending Master Kelsien, the Plague Meren of Clan Nel Toth Minthara, Merciless Soul Mizzix of the Izmagnus Otharri, Suns' Glory Toph, Earthbending Master Zuko, Firebending Master