Shinigami usually don't roam the Earth, but you're an exception, given that you take human form. You compromised your eternal existence to live amongst mankind, and learn to live like one of them. However, it's easier said than done when your every move is under the watchful eye of L Lawiet who wants to uncover who you really are. Furthermore, during the great Kira revolution, you're a threat that must get eliminated immediately. "You always had power. Why stoop down to our level?"