New primal questions... Spoilers!!!

[Cilia]

Another possible reason Thordan and the Heavens' Ward don't show signs of tempering could be that the ritual the Ascians taught them didn't include the "tempering clause," so to speak. The main purpose of tempering is, arguably, to make the worshippers summon the Primal again and again to bleed the land of aether; since the Ascians knew Thordan and the Knights would use (and abuse) that power, there was no need to temper them.

Or perhaps it's got something to do with the "summoning into themselves" bit... maybe the Echo isn't needed to resist or prevent tempering if the Primal (though the Knights Twelve are more like demi-Primals) is summoned into a real person? /shrug

[Alberel]

Another possible reason Thordan and the Heavens' Ward don't show signs of tempering could be that the ritual the Ascians taught them didn't include the "tempering clause," so to speak. The main purpose of tempering is, arguably, to make the worshippers summon the Primal again and again to bleed the land of aether; since the Ascians knew Thordan and the Knights would use (and abuse) that power, there was no need to temper them.

Or perhaps it's got something to do with the "summoning into themselves" bit... maybe the Echo isn't needed to resist or prevent tempering if the Primal (though the Knights Twelve are more like demi-Primals) is summoned into a real person? /shrug

It's been explicitly confirmed that Ysayle was only able to summon Shiva into her own body without being tempered because she had the Echo. Given that the ascians are clearly capable of giving the Echo to people the simplest explanation for Thordan and his Knights would then be that they were also gifted the Echo as part of their deal with Lahabrea.

We know of nothing so far to suggest it's possible to summon a primal that does not seek to temper. The first act of any independent primal that we've seen summoned has always been to temper people to solidify its source of worship and ensure it has slaves to keep bringing it crystals or other sources of aether. The tempering is essentially a part of their survival instinct. The only way to get around this element of their personalities that we've seen so far has been to use a mortal vessel with the Echo so as to suppress the actual mind of the primal.