You are Kin. You are above the law, above society, above everyone’s judgment but your own. You are the ultimate predator and the herd is humanity. Intelligence combined with powers far beyond that of normal humans means you go where you want, do what you want and answer to nobody.
You will never grow old and you’ll never die. Night after night, year after year, decade after decade. You'll watch human lives flit by in an eye blink. That is, unless you run afoul of an enemy, and you have plenty of those. All humanity would destroy you if they knew what you were. Monstrous beings, worse then any possible nightmare will hunt you as prey. And the most deadly of them all is your own kin, the other immortal beings who, like you pose as humans while they live the Nightlife.