Looks fun! Easy read, too.

I find the idea of using different rulesets for different worlds intriguing. Are these sets compatible with each other (I assume they are, otherwise planar travel would be impossible)? What are the differences?

Also, are the planes (like Summer and Winter and such) different per world, or do all the worlds share the same planes (allowing them maybe to function as portals between the worlds)? I also like the idea of each individual having his own 'planes'. You've probably already made some nice spells to invade someone's Mindscape.

Finally, have there been many 'nom nom' jokes?