So! Lore of the Apocalypse, aka Revelation, aka Dhar-Azyr, aka Dark Heavens, aka Fate Denial.
I'm going to do some random brainstorming, because I can, nah-ne-nah-nah. Feel free to add or dislike as you wish.
The Lore's main wind is Azyr, Winds of Haven and fate, with a lot of dhar backing it up. Probably some Shyish, because it's necromancy adjacent, and maybe some Ulgu, because we all have Misty Madam brain rot and the uncertainty element.
The Lore probably has a basing in Nehekharan magic, because instead of any Elf tradtion, because Princess Aelsabrim will likely have a limited education in such. There will likely be influence from necromancy, both the Vampire version and Luthor's Lore of the Deeps, which by-the-by I want to go into quest-wise.
The main theme of the Lore is "rejection of fate", either what has already occurred or will occur. Because Azyr, this will likely come with some weather aesthetics.
Spells might primarily be buffs or debuffs. For example, if we're using Total War Warhammer 3 style, a buff spell could apply "Cannot Die", which makes it so units (funnily enough) can't die. A debuff could prevent healing.
A fun damage type spell could be (hear me out) a reverse lightning bolt. Just, an explosion of lighting from below exploding up into the sky.