Fiery World

A world which was split apart by a fiery cosmic collision. A small part detached, and very few people lived through it. It basically became as a small moon. Perhaps there is a portal made by an evil wizard on the large planetary land so that he could establish a base on the small one – only to find that the remaining people there had evolved into a race of their own.

Small planet chunk would be difficult to live on – tough farms, few animals – lots of pestilent, hardy plants. Cave houses?

Larger, original 'mainland' would be a wealthier, rich land inhabited by fair and educated people with a very civilized, prominent government. Astrologers there knew about the part that detached, but it was assumed that there were no survivors.

so... was the collision was caused by evil magic?... and now, hundred of years
later, this wizard is trying to make it his base. The 'good' magic (religious government?) has decided to destroy this base with a modified form of the same (evil) magic. But the 'savage' people of this world don't want to be blown up by magic... they must escape to the mainland, or accept the powers of the 'evil wizard'. Do they actually reach it, or do they end up somewhere else?

Is this entire story just a question of what makes good 'good' and what makes 'evil' bad?

“we all watch the same moon and stars.”