#tempering

Lahabrea: The earth is fertile, and the seeds well sown. By my will, they shall reap salvation unlike any the world has known. Elidibus: By His will. Lahabrea: …By His will.

The Ascians in ARR and HW spend a lot of time telling the WoL about their One True God. Here though, in a moment of privacy before the Archon's arrival, Elidibus has to remind Lahabrea to check his ego as his actions are for Zodiark, not himself.

This is an early indication, alongside Nabriales's actions in the previous patch quests, that not everyone's on the same page in regards to the Ascian agenda. Nor is Zodiark's hold on each red mask absolute--even the ones initially at His summoning.

EDIT: Not to mention Fandaniel's actions in their entirety in Shadowbringers and Endwalker; killing one's god to usher in the end of the world is not the act of a tempered man!

Further doubt is placed on Emet-Selch's claim by Tiamat. We get more of her situation in the Shadowbringers patches, in the "Righteous Indignation" cutscene:

Tiamat: Recall, mortals, that it was I who did first summon my beloved, praying with all my being to bring him forth. You who contend with eikons cannot well be ignorant of the consequence. Alphinaud: …You too were exposed to his influence. That you are yet in possession of your own will is testament to the indomitable strength of your soul. Alphinaud: But were you to meet with Bahamut again, you fear you might succumb. Tiamat: Indeed. Ask the dragonslayer, and he will tell thee the power we of the first brood wield. Were I to lose myself to the eikon's influence, all would pay the price. Tiamat: But it is of little matter. For even had I the strength to resist, I yet lack the strength to break my shackles. This prison shall be my tomb. Alisaie: On the matter of Bahamut's influence, at least, I believe we can be of some assistance. Alisaie: If you're afraid of being enthralled, don't be─we have a cure. And while we've never tried it on one such as you, its basic principles are universal. Tiamat: Speakest thou in earnest? Alphinaud: There is no future for those bound to the past. Alphinaud: That you committed a terrible sin, I do not dispute. But if you feel remorse, you may yet make amends. We offer you that chance. Take it, or you will forever remain a prisoner, not of these cruel shackles, but of your own guilt. Tiamat: A chance to make amends… To lay Bahamut's memory to rest… Tiamat: When our own star faced annihilation, Hydaelyn granted us sanctuary. And now your foes would bring about Her destruction. This I cannot allow. For the debt I owe to Hydaelyn, and to all who have suffered for my sins…I shall fight with you, children of man.

Tiamat is a victim of the purposefully corrupted summoning magic the Ascians distributed. Yet she is not entirely enthralled by the Bahamut she summoned; she fears she would be if she were exposed further to a primal. Tiamat, as a Great Wyrm of the First Brood, is more akin in her aetheric composition to the Unsundered than most others on Hydaelyn. She knows she is influenced by the primal she summoned, and part of her remaining bound is to protect herself and the world from that consequence.

And then she chooses the cure and to move forward with her life, when given the option. As do other enthralled figures among the tribes when granted the option.

While there wasn't yet a cure when still fighting the Unsundered, entreaties to end their crusade and move forward fell on deaf ears--but I doubt very much it was due to Zodiark's influence entirely, and more their own stubborness after having clung to this course for ages.

The first cutscene of "Unto the Heavens" in Endwalker presents finally the intersection of original creation magic and modern summoning, as preparations are made to board the Ragnarok:

Livingway: You've done a fine job of readying the Ragnarok, but for it to take flight, we'll of course need the power of the Mothercrystal. Livingway: Given its immense size, however, transporting it would be an absolute logistical nightmare. Not to mention we'd need to shatter it into tiny shards for feeding to the engines. Livingway: But a brilliant idea came to me: we convert the crystal's energy into forms that can transport themselves! Urianger: Thou wouldst employ summoning…or should I say its precursor─creation magicks. Thancred: Care to explain for our benefit? Urianger: As you may have witnessed at Bestways Burrow, the Loporrits are capable of creation magicks, which they use to shape the moon's environment. Urianger: Yet simple though they make it seem, 'tis a highly advanced and exacting art. To perform it correctly requireth that the wielder holdeth the object in his mind's eye in clearest detail. Alphinaud: Hence the ancients' meticulous management of concepts. Urianger: Drawing upon this art, the Ascians conceived of summoning as we know it. Urianger: A derivative that replaceth the complexity of concepts with the simplicity of zealotry to make manifest a creation. Y'shtola: I see… By combining the Loporrits' magicks and the tribes' faith, we convert the Mothercrystal into primals of purer form and greater obedience. Y'shtola: Summoning as it was intended, one might say. Livingway: Indeed, indeed! Livingway: While Hydaelyn gave us the ability to use creation magicks, She forbade us from using it to make anything possessed of a soul─or similar. Livingway: She didn't say anything about fulfilling the desires of others, though. So! Borrowing our friends' faith, we'll create deities using the Mothercrystal's power, and send them to the Ragnarok! Alisaie: Am I the only one here concerned about the risk of being turned into a tempered minion? Livingway: Oh, right, I was getting to that… From what I've read in Sharlayan tomes, it appears the Ascians incorporated an additional nasty element into their summoning method: the fervent desire to assimilate others into one's belief. Livingway: Beings thus created are instilled with the selfsame desire, and use their powers to enthrall people─starting with the summoner. Livingway: In contrast, our creation magicks─the original and the best, accept no substitutes─don't incorporate any of that rubbish, so there's no risk of tempering. I mean, if the being was on the scale of Zodiark, you might feel a little “tug”…but I think we'll be safe enough.

From what we get here, summoning is quite obviously an offshoot of the original creation energies of the Ancients, but twisted by the thinness of the sundered mortals' aether and using faith and collected aether as a substitute. The tempering part was a later, intentional addition, possibly after the Unsundered had opportunity to examine the effect of Zodiark's summoning on themselves and extrapolating that.

Now, is some of this likely retconning to explain discrepancies in how characters acted and how tempering has been used? Probably! There was supposedly a rewrite of the main Ascian/Hydaelyn/Zodiark storyline, inherited from 1.0, which Stormblood allowed the time and consideration going forward on how they wanted to resolve this long arc. There's a lot in ARR and HW that has been recontextualized to fit, though some things still stand out a bit oddly; they did as good a job as they could, especially given the many years and writers involved.

But from the more recent writings, the intention is not to excuse the Unsundereds' actions with "they were tempered." And the final proof comes from Emet-Selch in Ultima Thule in cutscene #4 of "You Are Not Alone", having been through the preliminary wash cycle of the Lifestream long enough to have had various enchantments removed from him, while yet retaining his self before that too is washed out before reincarnation:

Alisaie: You're leaving!? Emet-Selch: Of course. The encore is finished, and I will not suffer myself to live again by Hydaelyn's magick. Emet-Selch: But more than that, the future you seek is not the past we loved. That is why we fought. And why I lost. Emet-Selch: But though you defeated me, my ideals are inviolate. Invincible. Emet-Selch: Spare me your pity. I have no use for it. If you would do something for me─save our star. Emet-Selch: See this tale to a triumphant conclusion, and with elation in your hearts, bid the final curtain fall. Emet-Selch: Only then may it rise again and a new tale begin─with new parts for all to play.

Through Shadowbringers, Emet-Selch claimed to want to cooperate with the Scions, while only giving bits and pieces of carefully considered information, and moving the goal posts whenever they did prove to him they were able to pass his tests and meet his expectations. It is not until this moment where, his duty to fight finished and the fate of his beloved world in any form at stake, that he is truly honest about what he did and why.

(I may also have an analysis WIP about comparing him and The Sandman's Morpheus and that stubborn refusal to change his mind and ideals, but it's slow going)

So while we mostly do have to go by what characters say, directly to WoL or to other characters in other scenes, each conversation cannot be taken in a vacuum; it is taken into account with their other conversations, with their actions, with other characters' input. And sometimes, the writers change direction, and new information will overwrite the old, even as it builds off of it.

The game is not consistent about Tempering and Summoning, though the double acts of Shadowbringers and Endwalker's story tries to clean that up. I just seriously doubt, from all the evidence, that the Unsundered were as entirely under Zodiark's thumb as say, one of Ifrit's over-hammered thralls and therefore not responsible for their choice and actions, the plans they made and came up with and clung to in stubborn guilt and grief and rage for so long they couldn't do anything else, even when presented proof of other options and chances to change or move forward.

Because another thing ShB and EW have shown us in both MSQ and in the Pandaemonium storyline, is who these men were, to become the Ascians we know, and how their own beliefs shaped them individually when faced with such loss--and how in each case, those past, pre-Zodiark selves would look at the eldritch beings they became by the Seventh era, and be horrified. Not because of any god's influence, but what they were capable of on their own.

...Well OK, Lahabrea already had a pretty good idea of what kind of monster he was capable of becoming. He also chose the worst way to handle it, and never seemed to learn from that. Elidibus and Emet-Selch though, while adamant in their beliefs, were also warped by what they chose to do and be, to where Elidibus even refused to remember his past to avoid the pain, tunneling into his duty with no wavering. Only Emet-Selch chose to remember, wallowing in it, acknowledging the monstrosity of his actions...and choosing to commit them anyway.