Evolution of races

Same here. The historical aspects of Athas should be beyond the scope of most PCs. Because of the way Athas was originally created as a kind of “historically neutral” setting, you could have literally any backstory for Athas. I’ve seen a ton of alternative historical backstories, from those involving the gods to the illithid empire.

And what is to say that Rajaat is the bad guy. Perhaps Rajaat was bringing peace and prosperity to the world, while his students perverted his preserving teachings into defiling.

Rajaat wanted to restored Athas to what he see as a better age (the Blue Age)… But his methods are quite harsh XD

If Sacha and Wyan’s words are true, after the Cleansing Wars the only one with the defiling powers would have been Rajaat himself. And we know that it takes centuries, but even defiled lands with time WILL become fertile again (I think that’s what happened to the Crimson Savanna).