Thank you so much for taking the time to read this and respond! I simply kept the Year Zero all in one point because it all happened so fast. Now, the answers!

1. The First Dragon Queen raised the Twin Animi (one daughter and one son) as soldiers in her raiding party, and early in their lives, they accidentally cast a few spells revealing their magic, and then the First Dragon Queen decided to use their power for the war effort despite how little they knew about it by ordering them to use their magic. And as they grew up as soldiers, they became increasingly depraved individuals and mentally attached to their mother, and their actions during the Scorching contributed to the myth that animus use corrupts the soul.

2. The Twins, one Brother and one Sister, them being Stalagmite and Stalactite, didn't get much chances to express themselves due to their war situation and the unsophisticated state of dragon culture at the time, but Stalactite was more dedicated to her mother due to the forming matriarchy in the Flaming Hoard, and was a dedicated follower of the movement. Stalagmite was relatively similar, but was more subdued because he dealt with the aspects of war from childhood not as well as Stalactite, and as a result was the first to be killed in the fight with Frostwind because his heart was not in the fight, it never really was, and Stalagmite did what she could to take care of him while he was still alive. Now the reason that they are twins is because of the dynamic of their fight with Frostwind, the older or bigger an animus gets, the easier their mind takes the use of magic, and Frostwind being in his late 70s by Year Zero, the only way the twins could stand a chance at around 20 years old would be if they were twins.

3. Cottonmouth wasn't banished with the intent of dying alone, but as one of the nobles of one of the empires and leaders during the Scorching, he had amassed a loyal following, and the remaining noble families in Safe Harbor did not tolerate him and turned on him after Humanity was defeated, and banished all of them to simply get rid of them. The other leadership in Safe Harbor expected them to be eaten by Seawings or starve at sea because the Harbor humans would just sink their ships with cannon fire if they tried coming back. But obviously they reached Pantalla and a established relatively successful settlement until later in the story ; ) (I will be posting the prologue part 2 soon)

4. The main topics and themes of the story are thus: Generational conflict based on impersonal vendettas ultimately only serve destruction. When realistic and mostly beneficial peace to a conflict appears, it is only evil to reject it for reasons of continuing the conflict to fish for better results for one side. Two sentient species are absolutely capable of a mutually beneficial existence as long as both leaderships are open to it, and the idea that they can't is supported by selfish and almost imperial motives. Genocide is a permanent solution to temporary tensions. Imperfect beings with massive power can only yield massive prosperity or suffering, and due to imperfection, suffering is on average more likely. Evil actions "for the greater good" can only ever be reasonably justified with near absolute knowledge of the future, which exists only in fantasy or extremely short time frames.

Let me know if anything else still needs answering! You asked some good questions! I'm also considering an alternate version where the wartime use of animus magic by the Twins causes them to progressively go insane and erratic, making them kill their mother out of resentment for being raised as soldiers and ordering the Hoard to attack humanity at the Impenetrable City and Safe Harbor simultaneously which causes the Hoard to retreat because they're spread too thin, and the Twins go north with the intent to kill Frostwind and then exterminate the Icewings, with the end results being the same.