Five Realms (Mer, Fairy, Dragon, Elf, Shadow) that 6 people rule. One of which is bad and the ruler wants to take control of the other 5. There are 4 Elders that rule the Mer, Fairy, Dragon, and Elf Realms with the Mind Elder living at the Center to oversee and make important decisions for all of the Realms.
Lord Draven from the Shadow Realm takes over the other 4 Realms and imprisons the 5 Elders. He rules as a dictator and changes the 4 Realms to an extension of the Shadow Realm. Four people (one from each of the 4 Realms) go on a quest to free all of the Elders from Draven and restore the Realms to their normal state. They succeed.
Everyone has magic
The Elders and their children have more powerful magic though (Elnora is the only child of an Elder)
Portals to the separate Realms
Shadow Realm portal = locked up and hidden from the public to prevent Draven and the people there from coming into the other Realms (this fails and the Second Elder War starts)