Even the best laid plans may go awry during the creating process, or get changed during the revision and editing phases. Everything is subject to change. I may find some more apt title along the way. Certain plot threads that were not entirely knotted off in the first book will be woven into the sequel. Many familiar characters will be active participants in the sequel, as well as some brand new characters who will be introduced.
History repeats itself, often for the worse.
Much that was once known has been lost or changed as one generation transitions to the next, often to the detriment of the current generation. A secondary but important theme might be how one person can effect change. I believe that fantasy, with all its archetypes, is one of the most empowering forms of literature. And continue writing. For me, it is a passion.