Or we could always have it that once you hit a certain power... Orochimaru himself seeks you out. Just like your master does when you hit a certain amount of experience.
Yes... I LOVE that idea.
I can even write the text if I have to. And I'll make it specially evil.
Like something about rumours... and how <playername> should slay Orochimaru. Orchimaru becomes angry and frustrated... and he hunts you down no matter where you are.
Of course.. It'll be more in depth.. Yes.. Yes... I can relish in the savory feeling of that. Heheheh...