Forbidden Magic: Darkness and Light!

[Ironhawk]

Im surprised you are putting Astral in the hands of Evil, rather than Good. After all, astral has a load of spells which are anti-undead: Solar Brilliance being the epitome of that class. Additionally, with the major exception of Ryleh, most astral heavy nations in the game (pyth, mari) are considered "holy", thematically.

IMO, the paths would break down like this:
Good: Nature, Astral
Bad: Death, Blood
Nuetral: Fire, Water, Air, Earth