Main Theme or Purpose?

Good day! I'm hoping that any lore experts here might be able to help me coming up with a main theme or purpose for a character that uses every class with all of the persona slots.

I've played off and on for since release and I'm somewhat familiar with different expansion elements. An overall theme or story here completely escapes me, though. Throughout Norrath's history, has there been an overall or continual theme or purpose that would drive characters (or personas) of every class to work in harmony with each other? Can anyone help me find this main purpose or drive that this character would strive for that would have all of his personas working together towards?

Unless I've missed something completely, I'm rather baffled by the complete lack of story here to explain personas. This is a pretty huge change in how character development works here.

With my extreme lack of knowledge here, I'm wondering if I can develop the latest incarnation of Agrippa into a character that would use every persona towards a main purpose or theme. If there is no real theme or purpose in official terms here, would creating the character to where he believes that the Nameless is directly or indirectly responsible for the chaos seen throughout Norrath's history work possibly? Has there been a time in Norrath's history that would conflict with this? Has there ever been a time in any expansions where adventures directly worked together in unison to serve the Nameless?

You could look at the story of the Monks. The founder of that order had mastered magic and weaponry, and thus developed the empty handed style to top it off, he even knew bard songs (whistling a bard song over his fists)