
Originally Posted by
Kyan
It should be noted that the term "tempering" is specifically for the process that Ifrit carries out on his followers
This doesn't seem to be true, as far as I can tell. A lot of the Sylph are referred to as Tempered. This includes all journal entries and FATEs.
Komuxio tells you that the wayward spriggan headed north into Larkscall, despite his warnings of hostile creatures and
tempered sylphs.
Sylphs
tempered in the levin-light of the primal Ramuh have descended into Little Solace to abduct their untempered brethren..
The sylphs, however, refer to these beings as simply touched. So, either Ifrit was the first being Eorzeans figured out was doing this willbreaking and they standardized his name for it, Lightning "burns" will away the same as Fire, or the development team just felt like calling Leviathan's tempered Drowned.

Originally Posted by
Rennah
Do we actually have evidence that ALL Serpent Reavers are tempered...?
Some...but probably not enough... The Sahagin and Leviathan have been a thorn in my side for a long time.
Let's start with some quotes and see how consistent those are with the rest of the story.

Originally Posted by
At the Gates
North and South Tidegate serve to protect the central and eastern parts of La Noscea from the Sahagin and their mindless servants, the Serpent Reavers, so it is imperative that the outposts are well supplied.

Originally Posted by
Feint and Strike
"Remember, no killin' the smallfolk, or it'll be your blood what stains Lord Leviathan's altars!"
These pirates you encountered with the tattooed faces... They call themselves the “Serpent Reavers.” Their ranks are formed of cutthroats and madmen who have
pledged themselves body and soul to the primal Leviathan.
Serpent Reavers are pirates who
take the Sahagin gods. What sorry sort of pirate
offers prayers to Leviathan? Like all zealots, their fervor grows with their numbers. Subtracting five fanatics from their fold ought to dampen their fire a while.
Though some hold a theory that some primals don't temper, they can't begin to claim Leviathan might one of them. There's "Drowned" pirates aplenty, and we know the Sahagin didn't become murderous until Seal Rock appeared (the same year Leviathan was first summoned, 1562). Aside from that, it's hazy as hells. Version 1.0 first hinted at tempering when Ifrit made others his thralls, which was foreshadowed by this line about the Reavers:
There have been fell rumors of the beast tribes abducting normal citizens and
brainwashing them into joining their ranks, only to use them as fodder in their petty wars. Let us hope they are but rumors...Though many say that the Serpent Reavers of Vylbrand are made up of traitors and brigands who betrayed their own kind
, could it be that they, too, are simply victims of this brainwashing?
So, we've got a hefty bag of evidence that the first Reavers were pirates who gave ear to the Sahagin thinking it would get them coin or power and ended up tempered just to be sure. Then they went hamlet to hamlet, burning, killing, and kidnapping more to be tempered. The thing is, in the Lominsan LV1-15 quests of ARR, you meet a kid who joined a pirate crew right before said crew's captain bent the knee to the Sahagin. Though this terrified him and he escaped at the first opportunity, he still identifies himself as having once been a Reaver. It's likely that there are "true" Reavers (who are Drowned) and that there are those who willingly take orders from (or are coerced into obeying) the tempered. Likewise, some are likely just doing business with the tempered and don't care where their gold comes from.
But it gets weirder for me. I can't even guarantee that most of the Sahagin are tempered. The beastmen daily quests for the Sahagin start out like the Brothers of Ash did; Novv's clutch has a different color than the others and refers to them as fanatical. However,
Novv himself was once the leader of the Coral Tridents - so it can't be so simple. Despite beginning his rampage when Leviathan was first summoned, Novv conquered for the matriarch's favor, not because Leviathan wanted him to.
Even the diplomatic Novv of today isn't entirely opposed to Leviathan. Were only some of the original Sahagin warriors tempered? Did the Coral Tridents only become tempered recently? Are we sure they're tempered now? The only way the story maintains consistency (as far as I can tell so far) is if we fill in some gaps with assumptions large enough to border on fanon.
I was so sure that Through the Maelstrom would tie up some loose ends, or at least not just make bigger gaps in the puzzle.

Originally Posted by
Rennah
If Madison was tempered, why would Denn kill him?
A bit of Devil's Advocate, but just because you can successfully brainwash someone into being a zealot doesn't mean you've brainwashed them into being smart and capable. Think of some real-world cults. Madison may very well have believed that Leviathan was the one true god and still not only have failed to hold off invaders of the pirate base but fled and let them give chase into sacred spawning grounds. Madison was weak, and a coward, and he brought adventurers under city-state banners directly to Reaver loading docks within Sahagin territory and asked Mr. Splashy to make up for his incompetence. He was more of a liability than an asset, so Denn neutralized him.