Why does Ysayle want to protect Nidhogg? (spoilers)

[Belhi]

I have a feeling it wasn't simply a utopia. You have to very different people together. Nidhogg though I have a feeling held a grudge towards mortals that predated the Elezen. I think he has issues that date back to the Allag. He tells Hraesvelgr that he told him not to trust the mortals.

The other thing I've been wondering on is Koji Fox said the lyrics of Dragonsong, the theme song, had potential double meanings much like Answers in what they refered to and Koji wrote them after he had seen what was planned for the story of the 3.X patch cycle. I'm wondering it perhaps Ratatoskr was attempting to maintain peace between the two races and Nidhogg manipulated things somewhat in hopes of triggering the war. He was the first on the scene.

That's not to say Thordan is innocent. Just that it was Nidhogg that set up the situation that allowed Thordan to do his thing.

[Yaichiro]

I have a feeling it wasn't simply a utopia. You have to very different people together. Nidhogg though I have a feeling held a grudge towards mortals that predated the Elezen. I think he has issues that date back to the Allag. He tells Hraesvelgr that he told him not to trust the mortals.

Before anything happened Dragons were fighting mortals but the the actions of Hraesvelgr and Saint Shiva brought an end to this war and I think Nidhogg was referring to this period of time when he said "Don't trust mortals".

King Thordan is not innocent and his actions cannot be justified. I don't think Nidhogg was setting up anything since the life of his sister perhaps equals the life of thousands of Ishgardians and it was a great loss to dragons when she was murdered. Don't forget that Nidhogg gained nothing from it and in fact he was almost got killed at that time.

[Cilia]

Well, for all we know Nidhogg has further bad blood with mortals, as can be inferred by his telling Hraesvelgr not to trust us [mortals] and the bits of Allagan machinery in the Aery. This, combined with the Guidance Node stating another dragon escaped Azys Lla at some point in the past (I forget the exact date) suggests Nidhogg may have once been held captive similar to Tiamat. He may not have wanted to start the Dragonsong War and may have been content just leaving the mortals alone, but he clearly went off the deep end after Ratatoskr's murder and his maiming; he's a sadistic monster during 3.0, and was probably the same for most of the preceding millennium.

King Thordan and the Knights Twelve' actions are by no means justifiable or forgivable. At the same time, that doesn't mean their children, and their children's children, for eternity, should suffer for it. Most modern Ishgardians (keyword: most) would probably be content to leave the dragons alone and fight only in self-defense. Aside from one slightly... deranged knight in the Western Highlands, we never seek out dragons to fight and kill for its own sake. The knights are generally full of bravado, but they appear to be fine with leaving the dragons alone.

In the end, the blame for the war lies on both sides. Thordan and the Knights Twelve killing Ratatoskr and maiming Nidhogg (to the point they actually believed him dead) cannot be forgiven, but Nidhogg (and Hraesvelgr through him) is not blameless for perpetuating an endless cycle of violence and death because he refuses to recognize that the people he's now fighting do not know why they are being killed and tormented and are more or less fighting in self-defense; or he simply doesn't care, and only wants to see them suffer more.

To directly answer the question, "Why does Ysayle want to protect Nidhogg?"
-She believes killing him will only perpetuate the cycle of revenge, similar to how us offing Tioman during our ascent up Sohm Al did. She has a point, but seeing as how Nidhogg is the origin of the cycle and the one most responsible for its perpetuation, cutting out the root of the problem was our best bet. (And it would have been, if not for Pope Thordan's lust for power and vengeance...)
-Alternatively, she did not want to kill Nidhogg because she cannot believe that her entire worldview (dragons are better than men) is flawed. The reveal that Nidhogg is little more than a sadistic monster, and later that Hraesvelgr is not blameless, completely breaks her.

[Februs]

King Thordan and the Knights Twelve' actions are by no means justifiable or forgivable.

The echo sequence about the surviving Knights Twelve and the two eyes of Nidhogg actually made me question this more than sympathize with the dragons.

The whole thing was kind of put aside in the subsequent cutscenes in favour of focusing solely on the fact that Nidhogg lost both his eyes and Hraesvelgr gave up one, but the Elezen knights they showed in that cutscene hardly seemed capable of plotting such a diabolical and sinister attack on Ratatoskr. Most of them were so disheartened by the events that they gave up their knighthoods and nobility in favour or common lives, and the ones who stayed only did so to keep the country from falling into catastrophe from lack of leadership in the face of possible Dragon retaliation. Out of all of the survivors, only one or two of them seemed even remotely "sinister" based on their behaviour in the cutscene, and even that's a stretch...

All in all, I'm more inclined to lay blame at the feet of the mastermind rather than those who got swept up in the plan. This means Theodan and possibly Nidhogg, as I don't trust that he had nothing to do with it until after the attack, and the possibility that there was someone behind the scenes pulling their strings. The reason I mention that is because someone might have told Theodan about the power of Dragon eyes and how it could be harnessed. He could have figured it out on his own, of course, but he could also have been manipulated into it by an Ascian or perhaps even Nidhogg himself (dumb plan, given he also lost his eyes, but he wouldn't have been the first villain to underestimate his chosen opponents). The echo can be frustratingly short on the small details sometimes. I'm hoping we get a better picture of it all when we track down and skin Nidhogg alive in subsequent patches.

[Frederick22]

I think there is more about the origin about the dragonsong war we still haven't seen. Did anyone take a close look to a guy called Marcechamp in Talifeather? Did anyone notice who does he look like?

[Dalvy]

I think there is more about the origin about the dragonsong war we still haven't seen. Did anyone take a close look to a guy called Marcechamp in Talifeather? Did anyone notice who does he look like?

As far as the AST chain goes, he tells us that Ishgard considers Tailfeather as citizens, but he holds a grudge because the city chooses not to send help nor medical aid.

[Frederick22]

As far as the AST chain goes, he tells us that Ishgard considers Tailfeather as citizens, but he holds a grudge because the city chooses not to send help nor medical aid.

Isn't that what I meaned. Anyway maybe was I tried to said is just a coincidence, but maybe not.
Seriously, nobody notice that Marcechamp looks exacly like one of the 12 knights?

[Belhi]

I think there is a common thread with the Celestial dragons that they are all trapped in the past. Tiamat is consumed by her shame and guilt, Hreasvelgr is a hermit lost in sadness and a sense of betrayal, and Nidhogg is consumed by hatred of crimes in the past. This is the flipside of the dragons perspective. They are so caught up in the past that it comes at the cost of the future. None of the Celestial dragons are doing a good job looking after their broods. None of them really seem to be thinking of their peoples futures. They are all caught up in their own issues.

I suspect that as the dragonsong war plays out, that factor will come into play. Probably the greatest thing the WoL can do for the Dragons is pull their leaders and elders out of the pits they have dug for themselves and remind them they have kin that depend on them for leadership.

[Nialle]

I'm pretty certain the entire Dragonsong War was orchestrated by Ascians.
The whole 'eat a dragon = get power' plan the knights went for sounds a lot like the shpiel Ascians use to get people to summon Primals. They put the idea into the heads of the first Ishgardians, I will bet on it.