@Kaarme
who were supposedly opposed to the war, to have the power to achieve what they did, they had to be one of the most powerful factions in the war
Or they just were powerful but not in the war? And after other factions wiped each other out they took the measures they did on the remaining populus. Not saying it necessarily went that way, but my point is there are other ways it could have gone down. You're assuming some stuff here.
consequently ones with the most horrifying spells at their disposal
This chapter establishes trained witches have the means, via the tower or other similar magics that may have once existed, to have pretty much any spell at their disposal. Doesn't mean they all necessarily use the worst ones. The whole basis of the past being described seems to be EVERYONE had access to knowledge/power.
Hell, it might have been that the only spell the group in question had that others didn't was the memory erasing one. If they came up with it first, they could essentially "disarm" any other remaining factions of their magical knowledge before they could learn about this new spell. If people aren't prepared for it I think that's a pretty game changing ability to have in a world dominated by magic. Both killing enemies and prolonging your own life is probably the first and primary means of magical power struggles, but I imagine that eventually reaches a sort constant and indefinitely escalating arms race. However they probably aren't looking into defenses against mental manipulation if they aren't aware it exists yet, and an effective way to nonviolently eliminate existing/remaining opposition is to make it so they don't know how to fight, the reason they were fighting, or that they were even fighting at all.
It's hilariously hypocritical to declare spells used directly on humans as forbidden, yet conveniently make an exception for a single one that serves their purposes perfectly
Okay, but to be fair, you're coming at this from an ethical perspective of someone not in a world where pretty much any one with a certain piece of knowledge could set off a nuke or make themselves immortal. The world that was being described sounded kinda... alien.
If anything I think what you're describing is too similar to how we envision power struggles in our world, which is dependent on possession and access to certain resources, organizations, and infrastructure. In a world where no such dependency exists outside of knowledge and ink, (and they seem to have been accessible to anyone) it could very well just be a sort of chaos where random, obscure groups could come in and out of prominence regardless of how power hungry or militaristic they were.
And then, how would a group that wants to maintain peace enforce it? In our world we can stop dangerous people from using weapons and WMDs by restricting the resources, equipment and infrastructure to acquire and/or make them. We can imprison criminals by denying them tools, means, and permission to freedom. If someone can kill people or manipulate physical reality with just ink and knowledge there's pretty much only 2 options for any sort of societal regulation. And given what was the norm at the time, those witches might have thought directly regulating knowledge was the obvious ethical solution.
If the world was flooded with tools that could do anything, and one of those tools essentially confiscated others' tools and the means/knowledge of how to acquire them, someone born into the norms of that world might come to the conclusion to ban every tool except that one, which serves as their means of enforcement. They might not yet be able to conceive of means to check, regulate, and eventually redistribute magical knowledge and power through a more nuanced nonmagical means.
And sure that solution might be hypocritical, but most means by which laws are enforced are hypocritical to some extent. Figures of authority and law enforcement often are allowed to suspend individual rights and use force on others (things society is generally predicated on NOT doing) so long as these exceptions are limited and clearly defined. Ideally society as a whole determines which exceptions are acceptable and which aren't while holding these bodies accountable, but the issue in the witches' case is that the means of enforcement is determined by a minority, while the very nature of the enforcement removes accountability, which is a pretty big issue.
You're right in saying that original group of witches probably weren't saints for doing what they did, at least by our standards. But again I also think the past circumstances described are pretty different from the ones we're familiar and the ones that modern societies are founded on; for all we know they may have been saints by the standards of their world at that time, or at least not actively nefarious.
I'm not saying they came up with the right answer, but that sort of widespread accessibility to absurd power on an individual basis actually poses interesting ethical and societal hypotheticals (which is also why I think it's an interesting implication of magic to explore). And disregarding that, I think even in our world you can't definitively say those who take control after a conflict were necessarily major players in the conflict itself (though it is rare for that happen). Overall I don't think it's as clear cut "they must have have done this and for this reason" as you're describing.
They monopolised the most powerful power in the whole world, establishing an unquestionable dominance over all the other people, king and peasant alike. They are free to do whatever they want and funnily enough nobody will ever know what they did because they can simply erase memories.
Now this by itself I think is valid skepticism. Even if I could argue that the extreme measures taken in the past may have been a result of the world of extremes witches had lived in up until then, I think over time if that sort of power disparity is maintained with no checks, it's pretty much inevitable that corruption and desire to control will grow, if it wasn't there already.
I just think that the degree to which you're willing to assume they've always been about being in power through insidious means might be a bit preemptive. Also I think that's kind of less interesting? Maybe some of those witches were like that, maybe some weren't, maybe it's changed over time, there's lots of possibilities. Don't jump the gun.
Maybe the war torn world was a hellish place, but their current one is only barely better.
Again, we can only speculate based on this chapter, but I don't think there's enough concrete information to say something like that definitively. And I think it would be a moot point anyway: even if things were way worse in the past that wouldn't necessarily justify continiuing the current unbalanced distribution of power. You can advocate against a monopoly without lumping it in with the kind of large scale Sodom and Gamora shit we saw in chapter 1. Regardless of degree they're both bad, and better solutions than either of them most likely exist.