There are some mobs in the Sahagin area that are "Drowned" so there's that.
Perhaps it is simply that we (our characters and the Scions) simply use tempering as a generic term to refer to the process because Ifrit was the first one that we ran in to. As far was what the Primals or their followers call the process, I agree that it should refer to something corresponding to their element.
Maybe Garuda's can be "Flayed"? But now that I think about it, I don't remember seeing any tempered forces in Garuda's employ. Or Titan's for that matter. I only remember Ifrit and Leviathan as having tempered forces. Even Ramuh seems to only be concentrating his tempering on the Sylphs.