A Contractual Relationship

So tell me what's the exact connection between you self-proclaimed Soloman's descendant and me, a normal college student? Don't explain something fiction-like to me, please. Wait, wait, wait. You have been my classmate for a year and I don't even know you? How could that be? And what's the red stamp on my neck? I have so many questions... OK first, why my roommate wants to kill me now?! (Source: WebComics)