A weird one.

I have walked through many wonders of this world, all throughout time. I have seen it all.
Or so I thought. For I have discovered you. There is nothing on this planet at any time more beautiful than your face, when contorted in a scream only achievable through the utmost terror. I have found a reason to stay in this world. For there is nothing in Hell comparable to this. In this, there are many lifetimes of entertainment. Yes, many lifetimes. For I shall keep you with me beyond your pitiful lifetime. Unknowingly, you shall be my plaything for millennia. You will, of course, die, as all you pitiful humans do. But I shall give you the gift of reincarnation. Well, it's a gift in my eternal eyes. A gift to myself. You shall go about your day-to-day life in a state of total paranoia. There shall be no escape, I will follow you everywhere. If you tell anyone about the terrible creature that has been following you, torturing you, they will put you in a nice, soft, quiet room. Well, it would be quiet if it weren't for your screams. For in that room, you and I would be alone.
I will enjoy your many suicides. It'll be a nice break, watching you torture and kill yourself. Because, of course, dying is no escape. The only outcome of death for you is a nice, fresh, new body, and total ignorance. A fresh start for me...
You'd better try get some sleep. You have a long day ahead of you.
Not that I'll let you sleep, of course.