Denebriel was also the most powerful blood mage.

I don't see any reason to distinguish warlocks and witches. Female warlocks and male witches just sounds weird. Usually, they're not gender-specific in works where only one is used. I've seen very few, if any, where both witches and warlocks are present and gender-neutral. I'm all for breaking conventions, but I don't think breaking this one is worth it.

Also, a little detail from DnD: The 3.5th edition of popular role playing game Dungeons and Dragons introduced a Warlock character class as well in the Complete Arcane, which gains its magic through a pact with a powerful and otherworldly being such as a devil, demon, or faerie, instead of the game's more traditional methods of faith, study, or innate power.

You've alluded to that in the Warlock write-up, but there's the simplification.

Also, this thread is being used for general re-write purposes (and some spam), what about Haidia?

I propose to have Haidia be akin to the Abyss in DnD Lore: One description of the Abyss presents it as a region of intense, extreme, and unforgiving climates, with layers consisting of overwhelmingly fierce desert sandstorms; explosively unstable volcanic activity, boiling lava, and molten rock; blinding, sub-zero Arctic glaciers; bottomless oceans filled with enormous leviathans; nauseatingly putrid environments saturated with disease-causing fungi; and the endless, existential void of infinite space.

We don't have to copy the 'layers' portion, but it could be a separate plane of existence connected to Althanas through various portals, with regions as described above. Sort of like the Gourmet World of Toriko, if anyone's ever read that.